Is there such a thing as too many water changes?

liuj1 said:

Hi all,

I'm on a quest to lower the nitrate levels in my tanks (currently at 25 ppm), and to do so, I've decided on changing 2 gallons of water every day in my 10 g and 4 gallons every day in my 25g. Right now, the pH/kH/gH between tank water and tap water is about the same, so i'm not worried about those going out of whack.

Assuming no drastic temperature changes, and if i pour in the water slowly enough as to avoid jolting the fish, will there be problems?

*as a side note, I don't plan to vacuum the gravel every day, just once every 2 weeks or so... replacing all the decor is a chore! Does vacuuming the gravel affect the efficacy of the water changes?

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I'll tell you what I do. I do a 50% water change every five days on my 29 gallon tank. I take out half of the total water volume, vacuum the sand, clean one of my two filters (leaving the other for the next time; alternating can save a screw up in the bio-filter), prune plants, pinch off dying leaves, wipe down the sides to clean off any algae, use vinegar on the underside of my hood and clean off the hard water deposits, then fill it back up. I prefer a 50% water change to a smaller amount simply because it works very well for me and plants need the trace elements out of the tap water anyway. Having said that, even if I had an unplanted tank, I would still do a 50% water change at least once a week (I do it every five days because I am a stay at home dad and so when the baby is asleep, I have some time to do it, so why not?) and vacuum the gravel thoroughly each time.

Nitrate is not nearly as toxic as ammonia or nitrites. If you want to get serious about water changes or if you need to due to high levels of ammonia or nitrites, you can actually do back to back, 50% water changes without harming the fish. As for vacuuming the substrate everyday, it isn't necessary. Obviously though, fish waste will be a culprit in producing nitrates so it would make sense to get some up every day if you're changing the water anyway. And, there is nothing wrong at all with vacuuming the substrate once a week as part of a regular maintenance schedule. i hope that helps you out, and good luck!

Assuming ingoing water is the same on all parameters as the outgoing water, there is absolutely no possible way you can change too much water or change it too frequently.