Can plants reduce water changes?

[captainandy]

Does a heavily planted discus tank decrease the need for frequent water changes. Plants naturally remove nitrates, metals and other chemicals from the water. And simple pruning transports these substances from the tank.
My planted tank (with MH and CO2 injection) requires weekly pruning, sometimes twice a week. Nitrates and phosphates are always close to zero. I make-up for evaporation losses with RO/DI. So why am I doing 50% water changes, twice a week. Anyone out there who doesn't change water and lets nature take its course.

[lesley]

You may find these articles of interest.

I am currently seeing how much the plants will use up the amonium/nitrates for me. I have removed almost all biological filter material from my filters, just left a sponge in each and have a sponge on the intake. If my nitrates go over 10 I do a large water change. At the moment I am changing 25% twice a week, and maintaining levels below 5 ppm. I probably don't have enough plants, cause other people here have to add nitrates! I am letting the fish tell me if they are happy or not. I have a snakeskin female who is especially touchy and goes dark the second the water is not to her liking!!!

http://www.aquabotanic.com/walstad/plants_and_biological_filtration.htm


http://www.skepticalaquarist.com/docs/nutrient/nitcyc.shtml

I would be interested to know as well, how often people with a planted tank that is running well change their water.

Lesley

[ChloroPhil]

Captainandy,

To answer your question, yes and no.

Yes, your plants will use up Nitrogen and Phosphorus and will do a good job of keeping the water clear of those chemicals. However, they don't do a great job of taking out the other biological materials that your fish are putting off, such as hormones. If your fish aren't growing much anymore you could get away with doing one 50% WC/week and everyone should be fine. If they're still growing then keep up those WC.

Doing WC 2x/weekly can only benefit your fish. Discus feces are very rich and can throw the chemical balance of an aquarium off quickly if not kept clean of debris. Especially with your MH lighting an imbalance can quickly create an algae problem that could be diverted by frequent debris syphoning. I've found in my tank that if I don't syphon up the feces BGA starts growing on/near it within a week.


To make a short story long you _could_ get away with doing fewer WC, but there's no reason not to do them more often. A good compromise might be doing one major cleaning 1x/week and then syphoning up the visible debris 2x/week. I'm not talking about getting down into the gravel, just running the syphon over the surface and in the cracks between wood and rocks where detritus gathers. Some mulm will inevitably accumulate in the substrate, which is good, but at least the substrate surface will be clear of debris and the water will be cleaner for your fish.



Lesley,

In my "Walstad" tank I don't do WC, only top offs. All my other tanks get a 30-50% WC 1x/week and my discus tank gets a 50% approx. every three days (whenever the sump gets low). These frequent changes aren't as much to keep the water clean, rather they're maintenance to help keep the nutrient levels in balance.

Best,
Phil

[M0oN]

Go out and get yourself a copy of "Ecology Of The Planted Aquarium" by Diana Walstad, she describes methods of setting up tanks that won't require water changes for 6 months and longer...obviously this wouldn't work for discus, but other fish...

Anyway, it's an informative read, full of information you'll never find anywhere else.

[captainandy]

Definately will get ahold of the Walstad book. To answer why not do the water changes....it's a matter of goals and philosophy. My experience with Discus is limited, however, I've been a SW reefer for years. My most successful reef requires very little attention. The combination of calcium reactors, deep sand bed and refrigium allow for little maintance other than feeding and top-off water. Without trying to sound so bold, I have created, thru lots of advice and a host of costly mistakes, a stable, beautiful ecosystem.

I just wonder why I don't see this type of thrust or mission with discus enthusiasts. Of course, breeding and rearing require the diligent attention written about. But just think how wonderful an accomplishment it would be to have a similar expeience with discus. Sure, it won't be a realistic habitat, but it would sure look neet.

[M0oN]

I don't see why it would be too large of a problem with full grown adult discus, but younger discus will not fair well in tanks that don't have daily water changes...

I personally don't want to attempt it simply because I'm too in love with my fish and would hate to get them sick...

I've got an apistogramma tank set up that I won't be performing water changes on, though.

[captainandy]

Why are discus so frail. Is it because of the extensive inbreeding? Are wild caugh or wild bred as high maintanance?

[M0oN]

Highly sensitive to nitrate and younger ones need a lot of mineral's supplemented for growth...somone else could explain it better...

[Don_Lee]

Some very interesting questions being asked in this thread....my personal view is like that of Moon, that juvenile discus would probably not fare well with less water changes. Honestly, I would be concerned even with adult discus. I have made some attempts to bend some of the hard and fast rules like the need for daily water changes, and for the most part I have failed utterly when I tried to do so. Experimentation is especially tough when the results of harming the discus occur.

Don

[captainandy]

Well, I am going to try an experiment on my 90gal planted tank. Inhabitants include 6 fish 4-6 inches in size, 2 juvys (half dollar size) and my clean-up crew including bristlenose, loaches, siamensis, nerite snails and about a dozen fw clams.
I'm only going to add flourish and top off water. Will measure parameters daily (temp, pH, nitrates, etc) and see what happens. Other than anecdotal advice, nothing has been offered to convince me that a heavily planted tank, with a good clean-up crew, can't keep the water in excellent shape.
Anecdotal observations are the quicksand of good science!

[M0oN]

captainandy, I would make a suggestion and encourage you to buy and read through "Ecology Of The Planted Aquarium" by Diana Walstad before attempting your experiment, I'm confident that it will help you out A LOT in successfully achieving your goal.

YOu can purchase it through http://www.amazon.com

[captainandy]

Great suggestion Moon

[captainandy]

By the way, the 4-5 inch fish were half that size a few months ago.

[M0oN]

It only takes around 12 months for discus to reach 8 inches or so, the first 5 months show really fast growth rates...which slows down slightly for the last 7 or so...

[ChloroPhil]

Captainandy,

Andecdotal evidence may be the quicksand of good science but until someone gets a few thousand dollars to pay for all the discus which will die in the process there won't be any experimental data to back it up.

Suffice it to say that not doing water changes will make your fish sick. Period. Why take that risk? There's no good reason to do so other than laziness. If what you want is a good technology driven tank, set up some sort of automatic water change system and let that do the work.

If you want Emperical data, I add 3/4tsp every water change to bring the NO3 levels in my tank to 7.5ppm. The fish bring it up to 10.0ppm and that's as high as the plants need it. Any more and algae starts growing fiercely. Will my fish die if the NO3 levels get even a little higher than 10.0ppm? No, but the tank starts looking like crap so I keep it down at 10.0 or lower.

You said you kept a pretty self sufficient SW tank in the past, am I right? Think about the stocking density of a SW vs. FW tank. If discus were SW fish you'd have 1 _maybe_ 2 adults in that 90g of yours. That's not even taking into account all the other fish. There really is no comparison between a discus tank and a SW system. They're to totally different creatures.

Here's a hard and fast for you, learned through experience:

In a 90g with 5 discus, 2 adults and 3 juveniles, feeding BW and Beefheart once each once a day (feeding 2x/day total), the fish were able to live with one 50% WC a week. Near the end of the week they were showing signs of distress which cleared up as soon as I started putting clean water in the tank. Furthermore, _every_ square inch of the substrate was covered in plants. In the areas where it was possible, the low growers were growing in layers 1/2" thick. That alone accounted for 27 cubic inches of plant biomass, _plus_ all the vertically growing plants.

That amount of Primary Producing biomass is more than sufficient to absorb all biologically created Nitrogenous materials in the system. Even then, when I had to add NO3 every other day to get a measurable amount, the fish were showing signs of distress by the end of the week. It wasn't until I did a WC that the fish recovered and started behaving normally and showing normal colors.

Here's another tidbit of info: The USDA says that 15.00ppm Nitrate in drinking water is safe for human consumption.

As soon as I started doing WC every three days the fish started behaving better all the time, showed better color, and grew faster than with 1 WC/week. This is as Emperical as it can get, I saw it with my own eyes.

Even though the plants were absorbing enough NO3 to necessitate supplimentation to the level of 5.00ppm (1/3rd the safe limit for human consumption) the fish were distressed.

The Moral of this story: Do your Water Changes!

Plants are the perfect buffer against "poisonous" compounds in a tank, but are _not_ a subsitute for water changes. If you don't do your WC and your fish get sick and/or die, don't come to us wondering why.

I'm usually pretty light handed, but on this subject I won't be. If I even smell a post about problems with fish/tanks related to not doing WC I will delete it no questions asked. We're here to learn how to keep our fish and planted aquaria in the healthiest manner possible. Not doing WC is not the way to do it. End of discussion.

[ChloroPhil]

Re: Diana Walstad:


Diana happens to live not to far from me and is actually very close to Wahter. Both of us are friends of hers and have discussed the idea of keeping Discus in a tank set up as she describes in her book and have come to the conclusion that it's a BAD THING!

Absolutely get the book. It's wonderful for explaining the chemical processes that happen in a planted aquarium. However, take it with a grain of salt. It's a great plant and general planted tank reference but should _not_ be taken as a reference for planted discus tanks.

Remember: Diana + Discus = BAD NEWS.

Thank you. :)
Phil

[M0oN]

Good advice Phil, like I said earlier I knew she did it with less delicate fish such as rainbow's and certain tangayikan's but never knew if she tried it with discus.

I simply love my fish too much to be willing to perform these experiments, personally I would rather try with a less expensive fish that is similar to a discus' requirements such as blue ram or peruvian altum's...

[ChloroPhil]

A really good test would be to do it with Cardinal Tetras, if there's a fish at all like a discus that's got to be it.

[M0oN]

I wonder why folks like you haven't compiled some information into a book for discus keepers Phil? It seems to me that there's very little information on the actual science of keeping discus, most of it seems to be directed at where they're from and what strains there are.

[ChloroPhil]

There are actually a bunch of books on how to keep discus. Unfortunately they're all aimed at keeping the fish, not the fish AND the aquarium. I'm thinking about fixing that though, we'll see. :)

[captainandy]

What an absolutely interesting discussion. Incredible that you can reduce the nitrates, phosphates and whatever, to near zero levels, and still, the fish don't do well. And it sounds as though a few of you have already conducted the experiment. You've convinced me to hold off on stopping the water changes. If nothing else, they're a great opportunity to vacuum the gravel. But I'd still love to learn what it is that builds up and causes the fish to do poorly.
I remember well when the Dutch started experimenting with wet/dry filters and this literally changed SW fish keeping. I remember when protein skimmers were introduced. There must be someone out there bright enough to figure out what's going on and how to fix it. It has nothing to do with being lazy, it has everything to do with delving into the hobby and learning.

[M0oN]

I know a few people fiddling around with a fresh water refugium that consists of daphnia and live plants etc.

Brewmaster is conducting experiments on in take nitrate filters...

I think it just has more to do with mineral uptake with discus, they have complex slime coats...

Perhaps if somone oculd somehow devise a three stage sump for a large tank that contains half of the volume of the tank the fish are in, consisting of a layer of clams, followed by another layer of plants that are known to take in large amounts of ammonium and nitrate with their own seperate lighting level and then a top level of free floating plants such as horn wort to help filter out debris and more nitrate...

[M0oN]

It would be cheaper to just devise a drip system that is constantly changing out the water 100% every 24 hours, though.

[captainandy]

A sort of aquarium toilet, in slow motion.

[M0oN]

A sort of aquarium toilet, in slow motion.


Exactly, it's what a lot of large scale breeders do, I believe there's a diagram under the do it yourself forum...

[stygian7]

I have a drip system set up on my tank; changes about 30-40gal/day in a 125 gal. tank. I don't have it change more than that because I'd be running the heaters nonstop. Also, it would make a dosing pump a necessity for the plants. Can't imagine how I lived without it. Still though, I do the 50% water change at the end of the week. I've got to trim the plants anyway, so why not have a python running at the same time. It only takes a few minutes to vaccum any noticeable detritus and then I let the hose run.
I don't have any scientific evidence supporting this, but keep in mind that there are other things in the aquarium than nitrates. I dose my tank with KNO3, K2SO4, MgSO4, and a trace element mix. The only things I test for are the nitrates (daily for now) and iron (occasionally). I have no idea what the levels of everything else are. Doing my water changes gives me piece of mind that they aren't building up to potentially toxic levels.

[captainandy]

Any chance you have a diagram or link to a site that shows your drip system?

[stygian7]

Sorry, no diagram or pics of the current setup. I recently changed it to get better circulation and filtration. Before, I just had an overflow that ran to the kitchen drain and a line filling the tank at the same time. I'm a student, so I set it up to be functional and save some time. I have the intention of refining it, but I've been so busy that it's still ugly enough not to be proud of. I will describe it for you though.

The tank has a set of overflows on it. Because my tank isn't drilled, they are the add on type. They operate in a normal manner and run the wet-dry filter. Underneath the tank is a 50 gallon sump tank. In the sump are the heaters, CO2 reactor, and a Wayne sump pump. The tank also has a float valve installed in it about 2/3 of the way up. I use the Kent float valve and have never had any problems with it malfuntioning. It works like this:

Line from cold tap water runs through a sediment filter and two carbon blocks to remove chlorine. Tank fills-because the sump is below the main tank, the added water raises the sump level. When the level increases enough, the sump kicks in and pumps the water down my kitchen sink drain.
A couple of notes:
I have the pipe running from the pump, through the wall, and into the drain before the trap, just to be safe. Probably not necessary as the pump is always submerged to some extent.
If you use a pump (not needed if you can keep your sump tank above the drain level), be sure to get the type that has a mechanical float switch, and not the tether type. My father has a tether type switch in his pond and it's always a problem. The mechanical type looks more like a toilet float with an inflexible attachment to the float.

[ChloroPhil]

That's cool Stygian.

Let's keep this discussion on topic, plumbing talk deserves its own thread in DIY.

Thanks,
Phil

[marinasta]

i think that 'dynamic aquaria: building living ecosystems' by adey and loveland is a cool book in terms of helping u understand how planted tanks work and what u can do to eliminate/decrease water changes. they describe algae scrubber approach. they maintained various tank set ups using this method. for instance they kept altums (pretty sensetive fish) in one of their s.american setups. there was also a discus in one of the pictures. they use this sytem on reef set ups as well. even though this method helps u eliminate water chages the set up itself seems to require a lot of work and patience to build.
another good reading on the subject is 'advanced aquarist guide' by ghadially. he described what he called a circulating range system where he used a daphnia tank connected to the main tank as a sort of filter substitute. he claimed his sytem was very stable. he kept different fishies including angels. dont think he kept discus though.
anyways, i dont suggest u use it on discus right away but it might be worth looking into. seems to me that someone who is experienced enough in these particular setups can eventually use it with discus as well. i know that lots of people would disagree with this.

marina

[Nightowl]

MOon, it would be interesting to see if it worked with blue rams or peruvian altums....2 fish that IMO/IME are way more sensitive to water quality/ chemistry than any discus I have ever raised.

Phil, please explain.... how is a cardinal tetra like a discus? thanks J.T.

[Nightowl]

I believe that's true of all fish, isn't it? I guess unless one is trying to induce spawning in a pair of discus... J.T.

[M0oN]

Tetra are just very very delicate fish, I've never been able to keep a decent amount of them alive for more then a few months...the slightest thing goes wrong and they're dead before you know it...

[jules]

I've never killed a Guppy or Platie with a bad water change, or even a Discus- but I have lost tetras. (it's unfortunate because they are a nice schooling fish).

[ChloroPhil]

Jules,

I picked the Cardinal Tetra specifically because it lives in the very same habitat as discus and Altum angels. It's a notoriously finicky fish that likes the very same conditions as discus. I figured it's better to lose a couple three dollar fish than a group of hundred dollar fish.