Filtration for Heckel Biotope tank

[illumnae]

What form of canister filtration would you guys recommend for a 120 gal Heckel biotope tank? I was previously running on an Eheim ProII 2028 and a Fluval FX5. The tank was converted from a planted tank, so the 2 filters were run for strong flow. Now that I've converted it to a biotope tank, I'd still like to run 2 filters, but am unsure what to use for the 2nd filter...what size would you guys recommend as suitable filtration that creates sufficient flow for the discus?

[erikc]

Okay, as usual you are probably going to get many different answers here.
I am going to give you what I would do if it was a tank for myself.

First thing I look for is the filter capacity. Since you are already equiped with cannister filters and want (I suppose) to stay that way I won't discourse on other types of filters.

I have found that with Heckels that the biological filtration is extremely important. I am an Eheim afficionado myself for the very simple reason that with either the Pro III or the good old 2060 I can put in about 10-12 litres of media into the filter !

With a 120 gal tank (450 litres) I would only have either the Eheim 2060 or the largest in the Pro III series. I would fill this filter up with fritted glass pellets (much larger bacteriological colonisation surface compared to other filter media) and just plain old synthetic wool to polish the water.

I never use the spraybar of the filters, but just set the outlet above the surface of the water, this creates sufficent current for oxygenisation (?) purposes without disturbing the Heckels (they really don't like too strong a current).

This seems to work for me, but as I said, you are going to get as many options as answers here ...

[Harriett]

You can use the FX5 here and also the Eheim. To dull the flow, you might try making a spray bar out of PVC for the FX5---run a pipe down the back wall that ends in a wide TEE about 20" wide [the actual spray bar part]. Cap the ends of the TEE, have the spray bar positioned so the water runs straight up the back wall--this will create a nice amount of water movement at the surface but will not blow the water / discus around. It depends on the size of the holes in the spray bar--smaller holes=more force, vica versa. Then run the Eheim spray bar from the tank short side down the length of the tank a few inches below the water surface. I have this going on a 180g and it works nicely. That is PLENTY of filtration for this tank and should work quite well for you!
Best regards,
Harriett

[illumnae]

Thanks for the feedback erik and harriett :) I did use the FX5 with a Eheim ProII 2028 (running both at the same time), but the FX5 died on me, so I'm gonna dump its carcass in the trash.

I'd like to use 2 filters together (redundency and easier to maintain one with the other kept running). Erik, would you think a 2260 with a ProII 2028 at the same time is overkill for the discus? The FX5 on its stock pipings was way too strong and my discus hated it. I had to turn the flow down to 1/2 of its full blast before the discus would venture out of the far corner from where the FX5 outlet was situated.

Instead of a 2060 with 10-12 litres of media, would 2x 2028 (14-15 litres of media) or 1x 2028 and 1x 2217 (12-14 litres of media) work out to give lots of biological filtration with much lower flow?

[erikc]

IMO the more filter media volume you have the better the fish will be. You can not have overkill as long as you can control the flow. If you have the budget, go for 2x 2028 (they will last you as long as your Heckels).

Heckels really thrive in a good biological system, the more media you have, the better they will be. But you must pay as much attention to the quality of the media as you did to the cannister. Fritted glass (usually in the form of spheres) seems to offer the best ratio voulme/surface area on the market at the moment and even though it is more expensive it is well woth it.

[illumnae]

I ended up getting a 2217 to run in conjunction with the 2028. It's almost identical to 2x 2028 as you recommended, just 600ml less media.

The media i'm using is Eheim SubstratPro, which are little cocopuff like balls of sintered glass.

[erikc]

I ended up getting a 2217 to run in conjunction with the 2028. It's almost identical to 2x 2028 as you recommended, just 600ml less media.

The media i'm using is Eheim SubstratPro, which are little cocopuff like balls of sintered glass.

Good choice, it should last you at least 15 years !

That's really good media, expensive but worth it. It comes cheaper if you get an Eheim media kit (which I suppose you got). Good luck setting it up and don't forget to seed you new filter.

[Apistomaster]

I'm another Eheim filter fan although I only own and use Eheim Classic 2217's because they can be a real bargain if you find them on sale. I also use as much of the Substrate Pro, sintered glass balls, as I can cram into one since they provide so much surface area throughout the balls for bacterial colonization. Using the largest Eheims you can afford is always a good investment. I bought the first Eheim model introduced to the USA market in the late '60's and have been sold on them ever since.

I also use a DIY wet/dry filter. I think a good wet/dry design promotes reaching the highest dissolved O2(DO) saturation levels possible for a given temperature but Eheim's have an edge when it comes to "polishing" the water. Discus are always happiest when there is a high DO level. Using the two filters allows cleaning them alternately so there is always sufficient nitrification going on; using only one filter, it is possible to have occasional mini-cycling problems after a thorough filter cleaning.
Using two Eheims allows one to alternately clean one well without creating any compromised nitrification cycles.

I use flows of 10X or more per hour tank volumes but there are a variety of ways to have high turnover rates without creating unwanted, excessive directional currents.

Good filtration is important but water chemistry similar to the Heckel's natural biotope will bring out their best colors. Heckels will thrive when kept in water with almost no dissolved solids and a pH of 4.5 or less is used. A pH only around 6.0 is not low enough.
Other Discus species exploit those kinds of biotopes. Heckels only range where the TDS and pH is at it's lowest. These are conditions for which Heckels are uniquely suited.
I know your public water supply is no longer as well suited for wild Discus as it was historically and that the recent changes have presented you with some new challenges.

[Frankr409]

Good filtration is important but water chemistry similar to the Heckel's natural biotope will bring out their best colors. Heckels will thrive when kept in water with almost no dissolved solids and a pH of 4.5 or less is used. A pH only around 6.0 is not low enough..

According to all of the chemistry reading that I have ever done on the subject of denitrification, the process is slowed below 6.5, severely impeded below 6.0 and a pH less than 5 stops the denitrification process completely.

Given that, would a bio-filter be recommended for the OP at a ph of 4.5?

[Apistomaster]

It is not true that biological filtration ceases to be effective in the pH range which is best for Heckels. I don't know how this began but it has been perpetuated by those who apparently have no experience keeping fish which require very low pH.
What is true is that an abrupt change from a pH closer to neutral to one around 4.0 will severely harm an established bio-filter. BTW, denitrification is the complete reverse of nitrification, the process on which all biological filters utilize. Denitrification requires an anaerobic environment and depends on an entirely different class of bacteria which in addition to a nitrate source they also need an additional source of chemical foods such as ethanol. Denitrification use is primarily used in reef aquariums as it is rather inefficient in fresh water aquariums.

There are many species of nitrifying bacteria. Each has it's optimal pH range. In any aquarium that is not sterile there will be at least some spores of nearly all species of nitrifying bacteria. If the aquarium is started out as a low pH tank or is GRADUALLY lowered to the pH range Heckels need, then those species of nitrifying bacteria will become the dominant types and life goes on. I would say that the bacteria which do make biological filtration are not as able to utilize high loads of ammonia/ammonium as the bacteria which do better at a higher pH so don't think you can overcrowd your Heckels and get away with it when keeping them in the same conditions they came from in the wild.

I have kept many tanks specifically intended for Heckels, Altum Angelfish, SE asian black water species and other fish which are from black water with a pH in nature sometimes even a bit lower than pH 4.0 for years at a time and without functional biological filtration I could not have done so.
This is in a zone which many fish keepers are afraid to explore but I can assure you that there are many others besides myself who do have plenty of experience with working with fish in water this acidic and it almost goes without saying that the water is also extremely soft. I have most recently been keeping a group of Black Darter Tetras, Poeciliocharax weitzmani and a group of about 16 of the tiny(>1 inch) Loricaridid sucker mouth catfish, Parotocinclus cf. epplyei together in a 20 long with a pH of 4.0 and a TDS ~15 ppm for the past year and a half. I use pure RO water not run through mixed bed deionizing filter cartridges. What little TDS is present is just what is left after running through the RO membrane. I have grown a lot of Singapore Moss in this tank and have harvested pounds of it over the time it has been set up.

Another experienced keeper of wild Discus bought the 10 Heckels I raised over almost 5 years from only about 3 inches to full grown adults keeps them in water as soft and acid as what I am using presently in this Tetra/catfish tank and those Heckels are gorgeous fish. Those who are serious about keeping their Altum Angelfish correctly use similar water chemistry. All of us depend on our biological filters. We just don't worry about the dreaded pH "crash" because water can't get more acidic than these values without help. Actually, my friend who bought my Heckels adds Muriatic acid to lower the pH of his RO water to usable levels quickly. You still have to continue making large, frequent water changes. That is where the muriatic acid comes in. You can drop the pH very low without much change to the TDS by using a strong acid. This would be impossible using the commonly sold pH lowering agent, sodium biphosphate which masquerades under many different brand names as an acid buffer.
I am one of the moderators of the wild Angelfish forum, www.finarama.com and using such soft acid water is pretty common among the more experienced Altum owners.
We all realize that to acclimate new fish or to alter an existing aquarium to support these kinds of fish that any changes must be carried out very gradually but once that becomes your "standard water" one doesn't worry about it anymore. it is difficult for beginners to believe at first and become comfortable using such water but doing so is in the best long term interests of these fish.
Green Discus also like very soft acid water but not as acidic as that which is normal for Heckels and it would be far to low of a pH of S. haraldi. That is partly why there are so few areas where their ranges ever overlap.
Many if not most plants will not be able to adapt to such soft acid water but I find that the Mosses do fine and there are some higher plants which also can thrive but the fact is that aquatic plants are not normally found growing in Heckel habitat so if a correct biotope is one's goal in a Heckel Discus tank then you probably don't have aquatic plants in mind to begin with.

[Frankr409]

Larry, I didn't do a good job of asking the question. I should have used the word nitrification, as obviously denitrification refers to the final conversion to N2.

While I would agree that the internet contains an abundance of misinformation, I came upon the statement that ammonia oxidation by nitrosomonas had a limiting point when a ph of 5.7 was reached.

I came upon this information in an article titled "Loss of Ammonia Monooxygenase Activity in Nitrosomonas europaea upon Exposure to Nitrite" published in October 1998 by APPLIED AND ENVIRONMENTAL MICROBIOLOGY, by the American Society for Microbiology. Fascinating reading, for sure.

I have since read more and less scholarly work that seem to suggest the same thing of bacteria in the Nitrosomonas family.

Are you of the opinion that nitrosomonas, the bacteria which breaks Ammonia into Nitrite does not have a limiting point, or that the limiting point is much lower than what has been stated by the ASM?

To your point that you, and other fish keepers have successfully kept discus at low ph levels is not in question, since the frequency of your water change schedule was adequate to remove undesired accumulations of ammonia and nitrite.

[Apistomaster]

Hi Frank,

I don't always change as much water as often as I should and my only mitigating factor is my use of biological filtration. Some times I only change half the water once a month in that Tetra/Parotocinclus tank; the only tank I currently keep in straight RO and at a pH of 4.0

I have never gone so far as to attempt to verify which species of bacteria are present in my low pH tanks but based on empirical experience, the filters still work. I still have zero ammonia, zero nitrites and increasing nitrates. I can only presume these measurements, taken over years, are possible due to a functional bio-filtration, nitrifying process going on on in my very low pH aquariums.

I would think out of all those who are keeping their Altums or Heckels in the low pH we have been discussing would have had some problems with ammonia and nitrites if it were not for their biological filtration as none of those i know are making large water changes daily. None are changing enough water to prevent measurable ammonia and nitrites from accumulating and Heckels and Altums are very sensitive to these chemicals.
I already said I don't think that biological filtration is as efficient at the lower end of the fish keeping pH range but it does work well enough to allow us to keep these very sensitive species. I am certain that our water changes are not sufficient to explain the absence of measurable ammonia and nitrites.

I lack as much interest in the process and specific bacteria involved because of too many years of empirical experience working with aquariums which have a pH at the very low end. I am accepting of the positive results I have had of my own and others whom I trust and have never made it a priority to discover why our biological filters continue to work so about all I have to offer is that some of us keep fish successfully at the lower end of the pH scale and all of us depend on biological filtration but we all tend to stock these tanks conservatively compared to how we would stock aquariums kept at a pH closer to 7.0.
So I am not able to provide any information about Nitrosmonas like what you found.
It does occur to me that if the study only used one species best adapted to a pH closer to neutral then it would begin to fail to be as effective as the pH becomes too low. My contention is that there are many species and some are better adapted to life at lower pH than those we depend on in less extreme environments. I don't know how else to explain the continued utility and indeed, necessity, of using biological filters in our lowest range pH aquariums since none of us have flow through water systems which would constantly refresh the water faster than the accumulation of ammonia and nitrites.
I suggest you try to keep a 20 long set up with sponge filters and stocked with some small species of fish from biotopes from extremely low TDS and a PH range of 3.5 to 4.5 and see for yourself the fact that biological filtration will remain an integral part of your system. There are many pretty Boraras spp, Parosphronemus, small, red wild Betta species you could try or some of the more extremophile small SA American Characins, a few species of Apistogramma like A. nissenji and catfish species from the Rio Negro you could try as your test specimens. Dicrossus filamentosus are well suited for a smaller simulated Heckel environment substitute. Coral Red Pencilfish, Nannostomus mortenthaleri are another candidate.
Many of these are as delicate as Heckels or Altums but their much smaller size and lower cost makes them better experimental species to see for yourself whether or not biological filtration doesn't still remain effective at a pH of 4.0 and a TDS >20 ppm.
If you decide to try using Muriatic acid to lower the pH be sure you prepare the water in a fishless reservoir as you cannot safely use it in the presence of the fish.

[Frankr409]

Hi Frank,

I don't always change as much water as often as I should and my only mitigating factor is my use of biological filtration. Some times I only change half the water once a month in that Tetra/Parotocinclus tank; the only tank I currently keep in straight RO and at a pH of 4.0

I have never gone so far as to attempt to verify which species of bacteria are present in my low pH tanks but based on empirical experience, the filters still work. I still have zero ammonia, zero nitrites and increasing nitrates. I can only presume these measurements, taken over years, are possible due to a functional bio-filtration, nitrifying process going on on in my very low pH aquariums.

I would think out of all those who are keeping their Altums or Heckels in the low pH we have been discussing would have had some problems with ammonia and nitrites if it were not for their biological filtration as none of those i know are making large water changes daily. None are changing enough water to prevent measurable ammonia and nitrites from accumulating and Heckels and Altums are very sensitive to these chemicals.
I already said I don't think that biological filtration is as efficient at the lower end of the fish keeping pH range but it does work well enough to allow us to keep these very sensitive species. I am certain that our water changes are not sufficient to explain the absence of measurable ammonia and nitrites.

I lack as much interest in the process and specific bacteria involved because of too many years of empirical experience working with aquariums which have a pH at the very low end. I am accepting of the positive results I have had of my own and others whom I trust and have never made it a priority to discover why our biological filters continue to work so about all I have to offer is that some of us keep fish successfully at the lower end of the pH scale and all of us depend on biological filtration but we all tend to stock these tanks conservatively compared to how we would stock aquariums kept at a pH closer to 7.0.
So I am not able to provide any information about Nitrosmonas like what you found.
It does occur to me that if the study only used one species best adapted to a pH closer to neutral then it would begin to fail to be as effective as the pH becomes too low. My contention is that there are many species and some are better adapted to life at lower pH than those we depend on in less extreme environments. I don't know how else to explain the continued utility and indeed, necessity, of using biological filters in our lowest range pH aquariums since none of us have flow through water systems which would constantly refresh the water faster than the accumulation of ammonia and nitrites.
I suggest you try to keep a 20 long set up with sponge filters and stocked with some small species of fish from biotopes from extremely low TDS and a PH range of 3.5 to 4.5 and see for yourself the fact that biological filtration will remain an integral part of your system. There are many pretty Boraras spp, Parosphronemus, small, red wild Betta species you could try or some of the more extremophile small SA American Characins, a few species of Apistogramma like A. nissenji and catfish species from the Rio Negro you could try as your test specimens. Dicrossus filamentosus are well suited for a smaller simulated Heckel environment substitute. Coral Red Pencilfish, Nannostomus mortenthaleri are another candidate.
Many of these are as delicate as Heckels or Altums but their much smaller size and lower cost makes them better experimental species to see for yourself whether or not biological filtration doesn't still remain effective at a pH of 4.0 and a TDS >20 ppm.
If you decide to try using Muriatic acid to lower the pH be sure you prepare the water in a fishless reservoir as you cannot safely use it in the presence of the fish.


Sounds like something is working Larry. Thanks for all of the information.

[illumnae]

I ended up buying 1 more Eheim 2217 to add to the mix. The eartheaters and discus sifting through the soft earthworm stick and vegetable sticks from kensfish created alot of floating sediment in the water, which is visually unpleasant.

I wanted to remove the floating sediment without reducing the bio-filtration, so I'm adding an extra 2217 in so that I have more canister room to add in lots of filter floss to trap the floating sediment/food. The filter floss will slow the flow in both 2217s, so hopefully it won't add up to too much flow for the discus!

On a separate note, the Heckels LOVE ken's vegetable sticks. They prefer it to the earthworm sticks, and the NLS Thera+A (which is their staple). The only thing they prefer more are FD Australian Blackworms

[Apistomaster]

I don't think there is much difference between the Veggie Sticks and Spirulina Sticks but my Heckels liked Spirulina Sticks. I keep in stock Spirulina and Earth worm Sticks. These two cover all my plecos and Discus as far as prepared foods go although I also use Tetra Color Bits. I also use Earthworm Flakes quite a bit. These are the only commercial foods I use. I buy bulk frozen blood worms and make a beef heart blend for the rest of the diet. I use them according to which fish I am raising. I have found that the L333 and L134 plecos should not be fed beef heart very often. They seem to have some trouble digesting it and some unexplained deaths have occurred among those which were being kept with Discus receiving a lot of heart. They like to eat it but they don't seem to be well adapted to processing raw heart.

[illumnae]

Hi Larry,

Spirulina sticks are mainly fish meal sticks with extra spirulina added in. The veggie sticks on the other hand are made from fruits and vegetables, with spirulina as a minor ingredient. After reading Heiko's book which states that fruit matter forms a large part of discus diet, I decided to try out Ken's veggie sticks. After the first feeding, they absolutely adore it.

My Heckels are still quite shy, and usually when I'm feeding them they'd be apprehensive about approaching the food while i'm still right in front of the tank. They eat well, but only when I watch from a short distance away. With FD Blackworms and veggie sticks, there's no such apprehension. They just charge in and eat!

What I hate about Ken's sticks is that they're so soft and crumbly that when the discus and eartheaters sift through them, I end up with lots and lots of fine suspended food in the water, which makes the tank look ugly for up to 2 hours subsequent to feeding time. It's annoying.

[tolga]

Hello Apistomaster, I have been watching some of the debates in this site and this is one of my first posts. I am interested in your point about the possibility of maintaining beneficial filter bacteria under conditions where the ph is likely to fall below 5.

I know that this subject has been briefly covered during some of the previous exchanges among experienced hobbyists on this site but your recent comments finally makes it clear that this is entirely possible.

For my planned project, I intend to run a Heckel biotope tank with low ph and my aim is to rely on biological filtration. Should I start the fishless cycling process with a high Ph (around 7 perhaps) and gradually reduce it to 5? or would it be better if I started the process with a Ph 5 at the outset? Are the type of bacteria that develops under higher ph values not the same as the ones that develop under lower ph values? or do some of the bacteria strains which develop under higher ph values go on to survive under lower ph values by gradually adapting to different conditions. I'm no scientist but I find the latter possibility not very likely, as I've been told that the difference between these ph values are huge to say the least.
I am minded to start with a low ph in the hope that this may work better. Please tell me what worked best for you. Also, would a closed circuit design involving the connection of an additional chamber with an oxydator (the hydrogen peroxide filled device used in the eighties) to the inlet pipe of the eheim professional thermofilter housing the biological media be any good? I thought that the additional source of oxygen might help matters. I hope these questions are still within the spirit of the thread. Thanks.

[Apistomaster]

Hi Tolga,
Addressing your last point first, I do not see how using any hydrogen peroxide will be of any use. My understanding is that hydrogen peroxide effects are mostly to raise the redox potential temporarily. I don't see how that helps.

I would begin at the same pH as you intend to use at all times.
At a low pH in the 4.0 range, the process of forming a fully functional biological filter will take longer than at a higher pH but if you begin at a higher pH it will take time for the bacteria best suited for the nitrification cycle will still take as much time to adapt as they would to begin the process at the lower range so I see no way of shortening the period it takes to establish them. In fact, there are no short cuts I am aware of with one exception and that would be if you inoculate the new system with bacteria from an already established low pH tank. I am the wrong guy to as about artificially or rather, a fishless cycling method. I never use that method. I prefer beginning with an extremely lightly stocked tank and let nature take it's course. One way would to split the difference. Begin with a few Rummy Nose Tetras and a few Checkerboard Cichlids, Dicrossus filamentosus and let them be your nitrogen sources along with any foods they may miss. That would begin the cycling and and take your time to adjust the to the lower pH range.
Alternately, you can begin with Heckels at somewhere in the 6.0 to 6.5 range and gradually bring down the pH and hardness.
It may take a couple months to reach the lower limits.
Once you are satisfied that you have established a viable low pH ecology you can add the Discus. The problem is that they would have be coming from a previously established low pH tank. That is why it may be simpler to use the alternate method I mentioned above. I have already acknowledged that the low end pH ecosystem aquarium will have a lower carrying capacity compared to those kept at a higher pH so you should allow more water per Discus than what is typically suggested for a more normal pH range.
Perhaps a useful analogy is setting up a reef tank where the bio-load is kept low and fish are a small portion of the inhabitants. The low pH tank is almost a biological desert and there is much less room for mistakes made like overstocking. And like a good reef tank, it can take 6 months to develop a thriving ecology. In other words, take your time and do not expect to achieve the desired results too soon.
You may want to try growing some Moss, Singapore or Java Moss. These will help introduce more acid loving bacteria and they often thrive in low pH tanks. I have excellent growth of Singapore Moss in my current low pH tank, a 20 long, stocked with Parotocinclus cf. eppelyi and Poeciliocharax weitzmani.

Be prepared to make as many large water changes as necessary to keep the ammonia and nitrites at zero and nitrates very low. Once the tank is fully stocked and the low pH ecology is well established, then you can probably reduce the water changes some.