General Aquaria Discussion • Water Changing

[Dbrianp]

Does anyone have a strong opinion about water changes?? I do about 1/3 every week, but I read somewhere that the change (especially with RO water) screws with the buffering and therefore PH. I've overdone the filtering. I have two Whisper EX 70's hanging on the back and a Filstar XP canister that does 300 gallons per hour, all for a 65 gallon tank. I test my water daily, like a lunatic. If my PH, KH and GH are right on and there's no trace of ammonia, nitrates or nitrites, what's the point of the water change??? Thanks!!!!!

[zimmy]

How are you testing the ammonia, nitrites and nitrates (ie. what kind of test kit)?

Is this a newly set up tank? Has it been cycled?....Is it heavily planted?

A cycled tank with fish and not a lot of plants will produce gradually increasing nitrate levels. The point of water changes is to lower nitrates and remove other waste products from the fish.

[Dbrianp]

It's been cycled. No plants. Lot's of test kits. An API strip, an API test tube/dropper thing, a Seachem Ammonia sticker thing and a Seacem test kit for free ammonia witH a tray and little disks. I think I have them all!!!!

[Dbrianp]

Also, both hanging filters have two bio filter traps each and the canister has ceramic disks and stars.

[DJRansome]

Having nitrates being produced is the proof that it is cycled because the beneficial bacteria produce nitrates.

I would not trust the strips and indicators...use liquid reagents. It's quite common to get bad nitrate results by failing to shake the tube and bottle sufficiently according to the directions.

I would change more than 30% weekly but I would not use RO water. What causes the need to use RO water?

Nitrate is an indicator of level of toxins, but there are other toxins you are removing when you change water as well.

[zimmy]

It's been cycled.

Did you get ammonia and nitrite readings while cycling?

[Dbrianp]

I did get readings, but it cycled quickly because I stuck a filter or two in there from a cycled tank. I use liquid reagents and I shake the #%$& out of them. Both the reagents and the tube. What "other toxins" are there???

[BillD]

There are all sorts of metabolic waste products in fish urine and feces, which we don't have the means to easily test for. Nitrate is used as an indicator of how often and how much water needs to be changed. You are likely to see that 40 ppm of nitrate is considered the high safe level. You will also hear stories of much higher levels with no adverse results. However, the one thing I have found constant with really successful fish keepers, is clean water, meaning low nitrate levels. Clean water helps fish grow quickly and without defect. The water can never be too clean, but, for most people a balance must be struck that allows them to maintain a reasonable quality without too much work. The nitrate test will help you determine the minimum requirements for your tank. Doing more than the minimum, will only help insure long term success.