Water changes

[brian p]

I am going to set up a 150 gallon discus tank. There will be sufficient mechanical and biological filtration. I intend to have maybe an inch of sand at the bottom, some wood but no plants. I need a variety of opinions on how often I will need to perform water changes and what percentage should be changed? I want to provide a margin of comfort but not get fanatical about changing the water. I would greatly appreciate your sage opinions.

Also, if I add plants, will this affect the frequency of required water changes?

[Carol_Roberts]

Juveniles grow best with daily water changes in a bare tank. I recomend adults for planted tanks.

The water changes are dependant on the fish load and the amount/type of food fed. Plants will not lessen the water changes needed.

With a single pair of discus and a school of cardinals lightly fed flakes and pellets you might get by with weekly water changes. 15 juvenile discus fed beefheart and bloodworms may need daily water changes

[Smokey]

One suggestion I might mention:

Using a Nitrate test kit; test the water and if the result shows Nitrate levels over 5 ppm; time for w/c.

It has been said that discus do not like water with HIGH NITRATES. Aparently 10 ppm of nitrates do have an adverse effect on discus.

I use the nitarte numbers to determine the w/c time and amount of water needed.

ex: I just did a water change. Removed 150 liters; then added 150 liters, of fresh water; on a 320 Liter system.

Before the w/c - NO3 = 8 ppm.
After the 50% w/c - NO3 = 4 ppm.

I will do another w/c in a couple of hours. To remove the remaining nitrates.

Generally this works out to a water change , of 50%, every 24 hours. According to the test kit.

The test kit gives me the information I need.

Especially after a heavy feeding of beefheart and bloodworms !!!

HTH.

Smokey

[brian p]

Thanks, Smokey.....this is precisely the type of "scientific metric" that I need to get a handle on this. It sounds like discus are more sensitive to nitrates than other fish. What about "nitrites" and "ammonia"? Presumably, as with other fish, nitrites are still the worst offender. Are you aware of any commercially available medium that reliably adsorbs nitrites and nitrates? I am attempting to create an environment with a certain amount of robustness so that water changes can occur with regularity, perhaps once a week and are not so hair-trigger and frequent.

[Smokey]

Yes, apparently discus are very sensative to the NITRATES. compared to other spieces. The Amazon is a very clean river. Huge .
If a tank is fully cycled; and there is sufficient bio-logical bacteria - both ammonia and nitrites will not be a concern.

NITRATES - the best way is still to do water changes.

I have played around with different ADSORBANT materials; in the long run water changes are much more reliable.

IF IT WAS EASY ... EVERONE WOULD BE KEEPING DISCUS !!! RIGHT.

Smokey

[brian p]

Smokey:

What about "protein-skimming" to get rid of some of the crud? Also, do you use peat to condition your water?

Many thanks.....

Brian

[Smokey]

Brian, Brian, Brian: the ultimate dream - minimum / water changes....

First; loose the sand. Discus do not like cesspools !
Second; Bare Bottom is the way to go .
Third; Rely on your personal expierence, then refine it 10 fold ! Discus are as hardy as any cichlid; if given the correct enviroment !

- A " Protien Skimmer" is only useful in higher density waters.
It is more efficient to remove the protien oils; skim the surface water concentration. AND have the surface protiens oils removed from the tank.

By the way; Your are talking to " Mr. Peat "!!!

Smokey

[dred]

Brian,

To answer your questions - yes, nitrites do pose a more serious concern to Discus. This is because there is less oxygen in their warmer water and we know nitrite makes it difficult for fish to use oxygen.

I personally don't believe that an inch of sand is completely unreasonable. I've got juveniles in two different tanks with a sand substrate. I vacuum each tank at least twice a day. And they are getting twice daily 40% water changes.

Discus need clean water to thrive. And, for a measureable standard nitrate really explains what your discus will respond to. Keep your nitrates low, and you'll have happy healthy discus. Don't and all bets are off - I imagine it will largely depend on how much your particular fish can tolerate. But, genetically, Discus built up no tolerance because they come from ridiculously pure water that is filtered by the roots of a rain forest; if that wasn't enough, it flows enourmous volumes of water. Remember that Discus have a relatively enourmous bioload. We get the best results by feeding very large quantities, frequently. And every time we do this, we are adding to the nitrate buildup in the tank.

So, if you want to get by with weekly changes in your 150 - keep your bioload small. Maybe 6 discus, some plants and some tetras. You can minimze the additional load by buying adult discus - because you can feed stingier.

Now is a good time be brutally honest with yourself about how much water you are willing to change. I'm lazy, so I built a lot of WC shortcut stuff. WC's aren't really that bad, and they are a great excuse to spend time with the fishies.

milton

[brian p]

Thanks, Milton. The picture is becoming progressively more "three-dimensional".

Brian