Bacteria Colonization - A Theory

[Cosmo]

After quite some time observing and considerable reading, I've come to realize a few things that I haven't seen in print. Since failure to account for what I'm about to present nearly cost me dearly, and, since it relates to several threads I've read recently, I thought I'd share this in the event it proves useful to anyone, and please, point out any false conclusions I may arrive at, I'm not a biologist :)

One of the things many find comfort in is providing either sufficient or an overabundance of bio filtration in our aquariums. I'm one who goes for massive overabundance, but the failure to really think through how bacteria actually colonize the filters resulted in near disaster.

I believe it's a generally accepted fact that bacteria colonies only grow in relationship to the amount of food available for them to eat. Consequently, the amount of biological filtration capacity you have mathematiclly available isn't necessarily the amount you actually have in use at any one given time. Providing over capacity simply allows for the growth of more colonies if the bio load increases. If it increases gradually, there's no problem, but if it increases faster than the bacteria colonies can grow... big problem.

If you have more than one bio filter in your tank, there's a good chance that neither one of them is seeded to it's full capacity, epecially if you're like me and provide double or triple capacity in filtration. In fact, one may be doing more of the work than the other depending upon flow, etc. Consequently, removing or exchanging one filter thinking the other will carry the load is not necessarily a safe assumption.

In my case, I had two large cannisters, each rated sufficient by the manufacturer to filter the entire tank on it's own. When I set up another tank, I replaced one of the cannisters with a duplicate one with the exception being the replacement filter wasn't cycled, believing the cycled one would carry the load while the "new" one cycled. With both filters rated to filter the entire tank, sounded perfectly reasonable and safe to me at the time.

Actually, what I had done was remove a large percentage (more or less half) of the bacteria colonies, leaving enough in the remaining filter to carry only a corresonding portion of the load that it was now required to carry. Since the two had cycled together, neither one had been allowed to culture sufficient amount of colonies to handle the entire bio load on it's own.

Due to this, and the fact that I had been distracted from my daily WC's on this tank while working downstairs on the fishroom ( :mad: dumb ) three days later I was hit with a massive ammonia spike, and spent the next two weeks fighting to keep from losing any fish. Fortunately, I didn't and they all were fine once the colonies grew in sufficient number to handle the bio load.

The fish that received the cycled cannister were fine since it was a smaller tank, and smaller and fewer fish.

I was reminded of this again the other night while reading a thread where a seeded foam filter was removed shortly after additional fish had been added to the tank. This tank as I remember also had a cannister and a penguin bio wheel, yet the owner experienced trouble the day after removing the foam filter. I think the same theory applies here if the fish were added while the sponge was cycling.

If the Penguin and cannister were cycled before the new additions, it would seem reasonable to expect that the foam filter picked up some of the added bio load when the new fish were added, preventing the other two filters from culturing additional colones as they otherwise would have been required to do. Consequently, the bio load increased but the colonies in the cannister and bio wheel didn't increase in relationship because the foam filter took some of the load for them. Removing the foam filter, then left the ecosystem short of sufficient bio capacity to handle the bioload of the tank with only the two remaining filters.

If this is a correct assumption, it would seem that seeding a foam filter would best be done in an already established aquarium without adding any new fish during the seeding time. Otherwise, if this theory is correct, removing the foam filter without removing fish would create a situation where the bacteria colonies can't grow fast enough to accommodate the entire bio load on their own and thereby causing potential problems for the tanks inhabitants.

Essentially the same situation that causes, or at least one of the causes, of New Tank Syndrome, or, the problems that develop when too many fish are added to an established tank at one time.

Does this seem like a reasonable theory?? It seems to apply at least in my experience.

Jim

PS. Yet another good reason to do daily substantial WC's, especially when adding new filters or fish :)

[Sergey]

Hi Cosmo,

Your theory makes total sense to me. The usual 'capacities' that are used to measure filters are not terribly meaningful when applied to biofilters. One may have large GPH and biomedia surface area, but bacterial population is going to match that of
the amount of ammonia and the amount of oxygen, so for a given bioload there's going to be a matching quantity of bacteria, spread over entire biomedia.

>If this is a correct assumption, it would seem that seeding a foam filter would best be
>done in an already established aquarium without adding any new fish during the
>seeding time.

I don't quite agree. It seems to me, if you put a new filter into an established tank, all other variables staying the same, you're going to 'transfer' some bacteria from existing biomedia onto the new one. Not physically transfer, of course, just some bacteria on the 'old' media are going to die off due to lack of ammonia as bacteria on the new media are established. So you might just end up with an ammonia spike in 2 tanks after you transfer you seeded filter into its permanent tank. Just how noticable a spike, I don't know how to quatify.

In seems safest to me to fishless cycle any new biofilter before fish are trusted to it.

Regards,
Sergey.

[Cosmo]

Good point on the seeding Sergey. My thought was that the foam filter if left in an unchanging bioload would seed only very lightly while the colonies in the established filters would remain somewhat the same. At which point, the foam filter would be seeded very lightly only when removed. However, your counter point actually makes more sense in the overall scheme of things.

Would it then stand to reason that the amount of time the foam filter was left in to seed would have a direct correlation to the size of the die off in the established filters and the growth of the colonies in the seeding foam filter?
After a time, if the foam were put into a smaller tank with a real light bio load, perhaps then only the seeding tank would be at risk rather than both ?

Totally agree with you that fishless cycling is the best method, but on the other hand having a seeding foam filter for emergencies seems practical for when you can't wait six weeks.

End of the day I think, so long as you maintain a good consistent WC regimen there would probably not be a problem in either tank ?

Thanks for the input and clarification :)

Jim

[brewmaster15]

Interesting discussion. I'll add a few more pieces to the puzzle..

Its been shown that pH and hardness affect the growth rate of the bacterial colony ..somene with acidic water will have a more difficult time establishing and propagating a bio filter colony.

Jim? what was the parameters of your tank?

Though I agree with you on the observations that taking out one of the filters removed some of the biofilter... don't forget to account for the biological filtration that occurs on the tank walls, and the surface of organic matter in the tank as well as just in the water table itself.

Also consider this. Bacteria doubles in hours, so it should not take long for a good biofilter to double its numbers and take up the extra bioload...in theory. In practice... the water parameters matter, as does the actual flow thru that filter...I think if you took half of that active cannsiters seeded material and placed it in the new cannister, and vice-a-verse... You may have not had any major issues.

hth,
al

[Cosmo]

G'Morning Al :wave:

The tank I referenced had very soft acidic water (ph 6.4) when I made the swap.. in hindsight had I swapped half populated, half new media into each filter I'm sure there would not have been a problem in the big tank.

Lack of thinking through the bacterial population issue, and, the fact that I was taking the cycled can to handle a tank of arriving juveniles was what started the problem. There was a third parameter leading up to the ammonia spike I hadn't mentioned cause it didn't fit in the original thought process, but since you're probably thinking an ammonia spike at ph 6.4 shouldn't have been too toxic - I had raised the ph in the holding tanks to 7 as the breeder suggested that ph for the new arrivals. Since I had skipped WC's for 2 days upstairs while busy downstairs :smash: I did a large WC on the third day with the higher ph water :smash: Think it was the combo of all things that made it hit so hard.

Not overlooking the bacteria in the water column and tank walls etc, was working under the assumption that these would remain constant irregardless but perhaps that too was an incorrect assumption ? Which leads to yet another thought...

Wouldn't a good regular WC regimen act as a catalyst that would tend to keep the bacteria colonies inside the bio filters at higher levels? Wouldn't the longer time frames between WC's allow more of the colonies to establish within the water column thereby reducing the number within the filters? Same thing for wiping down the tank walls ? Have to think that one through but on the surface (no pun intended :) ) it sounds reasonable..

Thanks for stimulating more brain cells ... they really need it early on a Sat. morning LOL.

Jim

[CARY_GLdiscus]

Great Topic Guy's I agree : )

[Sergey]

Hi Jim,

>Would it then stand to reason that the amount of time the foam filter was left in to
>seed would have a direct correlation to the size of the die off in the established >filters and the growth of the colonies in the seeding foam filter?

Absolutely.

>After a time, if the foam were put into a smaller tank with a real light bio load,
>perhaps then only the seeding tank would be at risk rather than both ?

Agree 100%.

>End of the day I think, so long as you maintain a good consistent WC regimen there
>would probably not be a problem in either tank ?

WCs dilute ammonia. Good for fish, bad for new bacteria growth. Since we tend to concenrate on fish here, WC in this case seems like a good thing ;)

>Totally agree with you that fishless cycling is the best method, but on the other hand
>having a seeding foam filter for emergencies seems practical for when you can't wait
>six weeks.

A combined method might be the fastest. As Al suggested, take some media from an established filter, put it into the new one, but run the new filter in a well-aerated container with warm medium hard medium alkaline water with some 5 ppm ammonia to provide bacteria with a massive overkill of food.
But then there seems to be a possibility of transferring pathogens with the old filter media into the new tank.


What is a bit frustrating in biofiltration discussions, it the lack of hard numbers. The basic factors affecting biofiltration seem to be well understood, but I've never seen any calculations on this matter. Not that I looked very hard, and I'm no biologist, too, but I'd assume if the numbers were known, people would've referred to them on a forum as concerned with water quality as this one.
We know that water chemistry (pH, temp, clorine), flow through the filter (not enough flow is bad, too much flow is apparently bad too as it flushes the bacteria away?), filter surface area for bacteria to colonize all affect biofiltration, but I've never seen any numbers put to any of this. And that's not going into any dynamics yet, such as rates of bacteria growth.
We tried to play with some numbers in a different thread on 'tankless fishless cycling'
http://forum.simplydiscus.com//showthread.php?t=41740 , but that didn't go very far.

Regards,
Sergey.

[Cosmo]

Sergey,

I was thinking of how the dilution factor would effect the bacterial colonies but find myself in a loop. The water change removes some of the colonies as well as some of the bio load, so, with the reduced amount of food do the colonies begin to die off only to grow again as the waste products buildup overnight, and, would the colonies in the water column rebuild faster, slower, or at the same pace as those in the filter?

My best guess is that it's a holistic effect where all colonies rebuild at more or less the same pace, so the net effect of the water change is more heavily weighted on removing waste and toxins while having little effect on the overall bio capacity of the tank. If correct, don't think you could ask for a better outcome :)

On subsequent filter startups I have mixed cultured and new media and have had no problems in either the "old" tank or the "new". This approach would be difficult I think when talking foam filters though. This does, however, give me a great idea for a new invention :D

If you want numbers and calculations, try and get Annonapersona involved in the coversation. She's a trained engineer and an absolute wiz :)

Jim

[Alight]

Very nice thread with some very accurate conclusions.

The only things I'd like to add are:
1) the nitrifying bacteria are almost entirely on surfaces, not in the water column. Any surface will do for them, the more surface area the better, and the more oxygenation the better (so the high flow in the filters, and the large surface area of the foam is great!).

2) the real nitrifying bacteria actually reproduce very slowly, which is one of the reasons they have only very recently been identified. This is also the major reason we have no numbers on where, how long, etc. It just hasn't been studied.

3) I would re-emphasize the importance of possibly seeding a tank you are about to put a heavy bio-load in with filter media, and sponge filters from an existing tank, and using ammonia to beef up the bacteria for 3-5 days (watching how quickly they eat it up using ammonia and nitrite testing) before you add the new fish.

4) taking filter media out of an existing tank can certainly cause a problem for exactly the reasons stated. I lean towards having an extra sponge filter in my tank, that has two power filters, both with sponges all over their intake tubes, and only using some of the sponges from the extra sponge filter for new tanks. They are only useful for a few fish in those new tanks to start with.

5) The reasons stated are the reasons that slowly increasing bioload is the only safe way to go, unless you seed your new tank using ammonia in a fishless cycling method. I wish I knew exactly how much ammonia various sized Discus produce in a day, because then I could use exactly the right amount of ammonia when I do seed a tank. Right now, I estimate that a single Discus can't make more than 10 drops of household ammonia in a day, and probably makes far less.

For some recent research articles on this issue, go to http://www.marineland.com/science/nspira.asp

[Sergey]

Jim,

When I mentioned WCs and how they dilute ammonia, I was mostly referring to the transitional period when you need to grow additional bacteria to bring the tank into an ammonia-bacteria equlibrium after some bacteria were removed with filter media. Once in equlibrium, the fluctuations of ammonia concentration because of WC are probably matched by bacteria population just fine, it seems, or the >=50% daily WC method would not work as well as it does.

Another logical observation seems to be that the bacteria floating in the water column of a typical discus tank is not a very significant %% of the population. I think so because the water is not turbulent and there's not much movement of water with dissolved ammonia and oxigen relative to bacteria. And I don't believe bacteria are good swimmers. That's why biofilters are designed the way they are designed, to provide a constant flow of water relative to sitting bacteria. A supporting fact would be that I've never heard of an ammonia spike after a near 100% WC.

Regards,
Sergey.

[Anonapersona]

Hi ya'll, looks like I'm late to the party and you've got everything all figured out!

I will toss out an idea for your consideration; how about taking a seeded sponge filter and squeezing it out really well into a bucket of tank water, just as you'd do for a normal cleaning. Then put your new sponge filter in that bucket to run for a few hours or even a day. You can return the old sponge to the old tank with no more disturbance to the biofiltration than a normal cleaning, and the new sponge will be fully innoculated with partially digested wastes and any bacteria that were dislodged during the squeezing. In a day or a few days, those bacteria should continue to multiply to consume the wastes you left in the bucket with them.

I have done this in a Q tank, but I just dumped the squeezings in on top of the new fish, which I think is probably not a good idea since that is a possible ammonia load of wastes along with the bacteria transferred.

I'd think that allowing the bacteria to settle for some period of time would be better, how long I do not know, at least 24 hours, maybe more. I suppose a simple ammonia and nitrite test would tell you if the bucket water was stablized, if it had no spikes, then you could move it to the new tank. You'd probably want to feed lightly and test regularly until you were feeling good about the sponge filter being well populated.

[Sergey]

Hi Alight,

Glad you're back on the topic! :)

>I wish I knew exactly how much ammonia various sized Discus produce in a day,
>because then I could use exactly the right amount of ammonia when I do seed a
>tank.

One minor ajustment I would make is that the amount of ammonia produced by a certain size fish is great for _testing_ if your filter is ready.
It seems much higher concentrations are better for boosting bacteria population.

Here's an idea. We could put a discus into a small tank with no biofiltration and watch ammonia concentration grow. But that might end up cruel if ammonia goes up too much. So why don't we literally learn from past mistakes? There're probably plenty of people on Simply who inadvertently staged this experiment. We would just need to find out
- volume of water
- water chemistry and temp, if known
- number/size of fish
- how much ammonia was detected and when.

Jim, could you provide our first data point?

Regards,
Sergey.

[Willie]

Its not clear to me why you had an ammonia spike in the first place. Did you measure ammonia levels during this time? Did the water get cloudy? As you say, ammonia is not toxic at pH 6.4.

In a fully cycled tank, bacterial population is not the limiting factor to nitrogen cycling. As ammonia levels rise, the same bacterial population is capable of processing more ammonia into nitrite and nitrate. As Al indicates, cell replication occurs in hours at 84F. If you quadrupled the ammonia level in the tank, the bacterial population should adjust within 24 hours. So I don't think you had insufficient bacteria.

Note that if ammonia levels drop, bacterial populations do not drop immediately. Most bacteria species will simply go dormant and die off is pretty slow. Recovery is remarkably fast.

Willie

[Cosmo]

Sergey,

Unfortunately I could give you all the data points with the exception of the last one, which is the one most germain to this discussion. My bio filters, when functioning normally, are extremely efficient (and I'm addicted to regular WC's as well) and I hadn't detected ANY trace of ammonia since the tank cycled 6 to 8 months beforehand. When the fish went into distress I ran to the basement for the test kit only to find the color charts had been destroyed when the basement flooded a month or so before. All the color charts were soggy and glued together... totally useless.

Consequently, I can't say for sure it was an ammonia spike or what the levels were, but since the symptoms were consistent with that and all the circumstantial evidence pointed to that.. that became my working theory.. I believe what happened in my tank that day was that the ammonia levels jumped significantly when the ph moved up over 7.0 after a couple days of the uncycled second filter and no WC's.. the bacteria didn't have 24 hours to catch up :(

Very interesting points regarding the dormancy period Willie, I had read that but completely forgotten :( This then would account for how the bio system addresses the slowly increasing ammonia buildup that begins to occur after a large WC? The bacteria remain alive so as the new water begins to become polluted they simply "wake up" and begin to eat again?

That would seem to suggest that during times of stable bio load and regular WC's the colonies either subsist or become dormant, and that new colonies grow primarily in response to large increases in the bio load related to such things as adding new fish or allowing the tank to become polluted with waste? Sound reasonable?

In hind sight what happend in my tank that day was essentially a case study of feeling too comfortable and overlooking some of the details regarding what mechanisms are in play and how they interact to maintain a stable environment. That is what got me to thinking so much more on how the bio filters actually functioned.

Do agree being able to project the actual waste an Adult Discus creates during a day could be useful information, but would think you'd need to be able to correlate that with the bacteria count in the system throughout the day as well in order for it to really be worthwhile. Don't think I have the equipment to to do that .. lol

Appreciate everyone pitching in here and adding to the conversation and the knoweldge base. I know I've learned from this so please continue sharing any more knowledge or insights you have. The more we all know and understand topics such as this, the happier and healthier our fish will :)

Jim

[Willie]

Bacterial ubiquity and dormancy is an amazing phenomenon. For example, 48 hours after an oil spill in the ocean, bacterial decomposition of hydrocarbons is the most significant factor in recovery. All this despite heavy wave action and near freezing waters. What the heck is the bacteria doing there in the first place? Nevertheless, its there and its population blooms very rapidly and to great effect. Most of the bacteria must exist in dormancy since replication could not account for such large populations.

As for ammonia, note that most of the production of ammonia come from the gills. Feces contribute ammonia only when they dissolve, so keep those bottoms clean!

Willie

[Sergey]

>Do agree being able to project the actual waste an Adult Discus creates
>during a day could be useful information, but would think you'd need to be
>able to correlate that with the bacteria count in the system throughout the
>day as well in order for it to really be worthwhile. Don't think I have the
>equipment to do that .. lol

I don't think it is necessary to go down into that level of detail. The question I seek an answer to is 'what's the fastest way to build a biofilter with sufficient capacity to fully process ammonia generated by X discus of a given size in Y gallons of water'. The traditional fishless cycling when ammonia is added to the entire tank seems like a huge overkill and might just be taking too much time unnecessarily.

To answer this question, it seems possible to abstract the bacteria away and treat the filter as a black box, with ammonia and oxygen as inputs and nitrate as output. I don't think it really matters just exactly what mechanism is at work. There are of course other situation when it does matter that we're dealing with bacteria, the fact, for example, that they can be killed with chlorine or antibiotics.
We just need to find out how the output of the filter depends on the inputs and the environment (temperature and water chemistry).
On the other hand, we need to find out how much ammonia is generated by fish to be able to say that we've built enough of a filter.

As far as building of the filter, it seems so far that the best environment consists of seeding bacteria and warm dechlorinated alkaline water with plenty of ammonia.

[Cosmo]

Sergey.. just crawled out of bed :o so probably not the best time to be responding :D but... if I understand your question then you're looking to quantify the fastest way to cycle a filter that would be capable of handling the bioload of X number of fish by manipulating the input during the cycling process ??

Couldn't this answer be obtained by setting up an array of filters in various size containers, varying water parameters, varying oxygen, varying temps, and adding varying amounts of ammonia and then simply testing each test vessel on a daily or twice/day routine? Possibly, you might even want to add different selections of bacteria growth agents to some vessels and not others to see if they speed the process?

From past experience, and fromr reading other threads, the amount of ammonia added during the cycling process doesn't seem to effect the amount of time it takes to cycle the filter (unless it's too little). Some even suggest adding too much ammonia is counterproductive. I know the first time I did a fishless cycle I added way too much and it still took 5 to 6 weeks. Maybe we should take a page out of a biologists notebook and use some sort of growth media? Like agar agar as well as ammonia?

But even the above test would then lead us back to the open question on whether or not the filter was seeded to capacity to handle the load of X number of Discus. Not sure how you'd ever be able to determine the amount of ammonia produced by an adult discus without subjecting the fish to possibly damaging or even fatal conditions during the test.

My suspiscion would be that length of time the filter is artificially maintained using clear ammonia would effect the bio handling capacity of the filter to a greater extent than would the amount of ammonia one uses to cycle the filter in the first place as that would provide more time for the colonies to develop.

Then again, it may not be possible to artificially seed a filter sufficiently to handle the sudden impact of the bioload of a large group of fish, which would mean fish would need to be added gradually. Even established tanks can be thrown out of balance if the bioload is suddenly increased by the addition of a large number of fish.

Another reason we do large WC's, right :)

Jim

[Cosmo]

Willie,

You bring up an interesting point related to a point I raised in a previous thread I called "Turdology" regarding observations that the turds of fish fed exclusively CBW's seemed to disolve while fish fed foods such as frozen bloodworms formed large solid turds. Perhaps the better way to describe the CBW induced feces would be to say they disolve faster as they all eventually disolve.

This being the case, while CBW's aren't supposed to foul the water if not eaten as do frozen foods, the waste produced by their consumption would be released into the water column faster after the fish consume, process, and expell them.

Yes, all turds should be removed as quickly as possible, but this would suggest that feeding CBWs gives you a smaller window of time to do so before the ammonia is released into the water, tending to at least partially offset one of the benfits of feeding them.

The benefits though... fish LOVE them, growth, etc I think still outweigh the downside of the melting turds so long as one keeps up with their maintenance :D

Jim

[Sergey]

Hi Jim,

>if I understand your question then you're looking to quantify the fastest way to cycle a
>filter that would be capable of handling the bioload of X number of fish by manipulating
>the input during the cycling process ??

Precisely. Inputs and the environment.

>But even the above test would then lead us back to the open question on whether or
>not the filter was seeded to capacity to handle the load of X number of Discus. Not
>sure how you'd ever be able to determine the amount of ammonia produced by an
>adult discus without subjecting the fish to possibly damaging or even fatal conditions
>during the test.

Exactly. But now thinking about it, there's probably a way to figure out the filtering capacity of a filter by observing the outputs, i.e. measure nitrate concentration in a tank with X discus and a working biofilter, without stressing the fish. I need to give this more thought.

>Then again, it may not be possible to artificially seed a filter sufficiently to handle the
>sudden impact of the bioload of a large group of fish, which would mean fish would
>need to be added gradually. Even established tanks can be thrown out of balance if
>the bioload is suddenly increased by the addition of a large number of fish.

It's definitely correct that en established tank can be thrown off balance by a lot of new bioload, but I as far as I understand, usual fishless cycle puts so much ammonia through the filter that the bacterial colony is huge and can take a big bioload immediately. It seems some bacteria die off or go dormant as it's been suggested after the cycled filter is put into normal operation in the tank, because fish don't produce as much ammonia as was used during cycling.

Regards,
Sergey.

[Alight]

Both the idea of using the amount of nitrates built up per day, and the idea of using someone's bad experience with an uncycled tank are very good.

I think the nitrate build up may be the best. See how fast the fishless cycling ammonia is building up nitrate, and compare with how fast x number of Discus build up nitrate.

The only problem with this latter one is that many nitrate test kits count the ammonia as nitrate, and it's really hard to tell exactly how much of the test was nitrate. However, if the ammonia level is constant (maybe only test when the levels go to zero each day) it could work.

Seems like there might be someone who has done the first test, too, if only we could get them to post their results. The best test would be a completely uncycled tank where no nitrates are being produced.

There is some more biology going on that is important, besides the direct ammonia contribution to the nitrogen cycle. This is what most of the other "cycling" aids work on.

The excess food and feces have virtually no direct ammonia in them. They are broken down (all protein has nitrogen compounds in it) by bacteria into various compounds, one prominent one of which is ammonia. These are not the same bacteria that build up ammonia into nitrites, which are not the same as the ones that build up nitrites to nitrates.

Without these bacteria, wastes in a tank will not be transformed into ammonia. These bacteria do reproduce very quickly (unlike the nitrifying bacteria that work on ammonia and nitrites) and are the ones responsible for cloudy water in new tanks.

The fishless cycling method does not build up populations of these, so a fishless cycled tank may still go through a cloudy water stage, if a high bioload is added quickly. This is a reason to use seeded sponges, squeezings, etc. if possible. Obviously, if you are trying to set up tank, and want to prevent contamination from some pest you have in your existing tanks, this becomes problematic.

I don't know if BioSpira contains any of these other bacteria, but I know that some of the other cycling agents do (in fact, that's all they really contain, because the nitrosomonas they contain are not the true nitrifying bacteria, as recent research has discovered. The real bacteria is nitrospira.)

[Sergey]

I obviously missed the organics-eating bacteria altogether. What's the downside of missing those in a new fishless cycled filter? Is it just that the water doesn't look good for some time or there's something more substantial?

Regards,
Sergey.