Is it possible to do too many water changes and have it take a negative effect on your tank? Let's say the water is always fully treated for chlorine/chloramines. What would the affect on plants be? Affect on fish?
This is my opinoin and certainly open for debate, but:
Yeah, absolutely. You're destabilizing the environment every time you do a water change. Unless you're unbelievable careful, the nutrients and chemical compostion of the water will change every time regardless of whether you're using chlorine nuetralizers. All creatures are accustomed to a somewhat stable environment with occasional fluctuations. By changing their environment frequently, you'd stress them out and stress has major negative affects on all living things.
How many water changes are we talking about here?
A lot of discus keepers change water a lot more frequently than the rest of us do, but I would think that over the generations the fish have become accustomed to it, and I think that discus keepers in general are really careful about it.
In nature, everytime it rains the water changes in parameters, so changes aren't harmful to the fish or plants. Change water as often as you want, but be sure to use a dechlorinator each time, and keep the incoming water reasonably close to the same temperature as the tank water.
Solstice - what you are thinking is probably the opposite. Usually systems that frequently change water are the most stable. If you change your water once a month or less then for sure the system will change every time. But with a continuous water change setup the system doesn’t barely deviate from your tapwater conditions. Better to adapt your fish to your tapwater than let them go and cause greater changes with infrequent water changes. I'll probably be switching to the daily auto water change on my next aquariums, any less I have to manually do when it comes to tank maintenance and water changing the better.:wink: Most folks here do atleast 50% weekly water change. And so far that I have been doing that I have completely changed my mind about its importance (before comming to the forums I thought doing that much water changing was crazy).
If I am up to it I do water changes 3 times a week but only 10-20%. I do it manually, and pump water from a big garbage can in my fish room. I always vacuum debris from the tank. I only match the temperature, but otherwise it is strait out of the tap. I have a well, so there's no chlorine.
I figure my fish are accustomed to this and suffer no ill effects. I agree that infrequent water changes are more problematic as there is a greater mismatch in the chemistries.
I change 80-90% of the water in my tanks weekly. Been doing it that way for several years. I use prime to declorinate and adjust the temp to close the tank water. I have noticed zero problems. I have had no loses and all the fish and fauna thrive. YMMV