baker360360 said:
Agree with above posts that water changes of twice a week is certainly not too much.I only do one water change a week, usually about 35% and have to say I actually quite enjoy doing W/C once a week at weekends as find it quite therapeutic!
As for your friend doing water changes once every 2 weeks or worse at once a month, little wonder then she having problems with fish illnesses.Twice a week is good, twice a month is poor! Simples!
Sounds like hard work and risky ( too get new water perfectly matching). Our filters do most of the cleaning and we do water changes to rid of the nitrate as there shouldn't be any nitrite or ammonia. If done once a week then your nitrate will be well in optimal levels. Also it should be enough to clean any algae/solid waste ect. If substrate is cleaned too often and you don't supplement the plants how are they going to get nutrients?
No filter can extract 100% of accumulated waste material from any tank.
What the filter does is to remove/convert harmful ammonia and nitrites to nitrates as the bacteria basically lives in the filter you are doing no harm in doing twice weekly water changes as long as the filter remains relatively untouched and only a gentle maintenance clean occasionally depending on your type of filter.
You are absolutely correct in saying water changes is to remove harmful levels of nitrates but that is not all what water changes does.
What this boils down to is, the frequency of water changes you need depends on your stocking levels and filtration.
For example, someone who keeps goldfish or perhaps several large plecos which are messy fish, the tank would definitely benefit with twice weekly water cleans.
Cleaning substrate depends on how you gravel vac the substrate, if too deep and too often, then there is a faint possibility you may remove too much nutrients from the plants. Gravel vac once a week is fine and just do water changes and clean glass for the other weekly water changes would be practical way of doing things. Also adding plant ferts may help to compensate for over cleaning substrates.
My tank for example has a TetraTec Ex1200 for a 90 litre tank, so I can say it has excellent filtration capabilities and my stocking is Threadfin Rainbowfish and RCS and a few assassin snails, once a week water changes of 35% is pretty decent.
BUT if I had a pleco or two in my tank for example then I would rather do 2 water changes of 35% a week with the same filter setup.
If you have low stocking levels then once a week water change is perfectly fine. I don't agree with water changes once every 2 weeks or even once a month, hence why I say water changes twice a week is certainly not too much, however more than that may be a bit overkill.
What works for one person might not work for another.