Thinking of Dropping from 50% to 25% weekly water changes

I was at my LFS today and their opinion is that nitrates of 40 ppm is plenty low enough. I think 25% weekly water changes will be sufficient to keep peak nitrates below 40 ppm. In addition, my source water is about 8.2 pH. I have driftwood in the tank and I think that will lower the pH a bit. But not if I am doing 50% weekly water changes. And if it does, then my weekly water changes may create a bit of pH shock.

Therefore, I am thinking 25% is good enough so long as my nitrates do not get too high. Based on what my LFS says, I am even thinking that peaking above 40 might not be the end of the world.

I know there are a lot of folks on here who are big believers in big water changes. Bring it on!

 

Some fish are more sensitive to nitrates than others, I have found for example guppies are better with nitrates under 10-20. Try lowering your nitrates and keep an eye on them whilst doing 25percent water changes, if they rise each week then you need to do bigger changes.

 

I estimate that I am producing about 10 ppm per week. If that is accurate, my nitrates would stabilize at peak nitrates of about 40 ppm. 25% WC down to 30 and back up to 40 by the end of the week.

I am keeping guppies so if they are sensitive to nitrates, that would be relevant to me. However, mine are feeder guppies so perhaps they are not as sensitive as fancy guppies.

 

Even in a planted tank I wouldn’t recommend nitrates higher than 20ppm. Needless to say your pH effects the strength of nitrogen on your fish

 

Needless to say your pH effects the strength of nitrogen on your fish

Not needless to say for me. I am a newbie. How does it affect the strength? In a good way or a bad way? Do you mean strength of nitrogen or nitrate?

 

Not needless to say for me. I am a newbie. How does it affect the strength? In a good way or a bad way? Do you mean strength of nitrogen or nitrate?

Increased nitrates will lower your pH, if the pH goes lower than 6.0 your aerobic bacteria will have a harder time processing ammonia possibly causing your fish to die of ammonia poisoning

 

Sorg67 this is my opinion and I never judge nobody as we all learn by our own experiences in fish keeping or life

Any form of guppy can only deal with up to 20ppm and if you get it lower all the better but why not try a 30% water change and see how it goes from there.

 

Sorg67 this is my opinion and I never judge nobody as we all learn by our own experiences in fish keeping or life

Any form of guppy can only deal with up to 20ppm and if you get it lower all the better but why not try a 30% water change and see how it goes from there.

I agree with Tez

 

I do weekly 50-75% WC's regardless of what my parameters are.

 

Water change volume depends on stocking level & type of fish. A 50% WC would be appropriate for a 75 gal tank stocked with 30 Mbuna cichlids. The same tank with 30 Neon Tetras might do fine with a weekly 25% WC. Just use common sense.
The 8.2 PH in your tank probably won't budge unless you have an unusually large amount of DW in the hardscape,

 

A 50% WC would be appropriate for a 75 gal tank stocked with 30

Well i've got a 60 gal now with 31 fish and will do a 40% when I know my water as done more cycling a bit.