water changes

That sounds about right. A lot of work but you will get better fry for it and a better survival rate.
 
The key is to manage nitrates so that they are at a reasonable level. For many of us, we consider below 20 ppm to be a good "goal". With some people, they are happy to have nitrates below 30-40 ppm. Regardless of your situation or how much experience you have had in this hobby, keeping the nitrates under 40 ppm would be a good goal until you figure out what needs to be done to insure you can manage the water chemistry accordingly.

Some people with a heavy bioload just never see low nitrates, and that is fine unless you are dealing with under-filteration or nitrates above 40 ppm. Then there is reason for concern.

Good luck! ;)
 
How about this scenario:
A 2 foot Cichlasoma Dovii alone in a 300 gallon aquarium. If nitrates remain at 10-30 ppm doing only 15% weekly water changes, will this be enough to keep the other toxins, etc at a safe level?
 
I would be concerned, in that scenario with the pH of the water. I know that with my low buffered tap water if I do not do at least a 25% change weekly then my pH starts to crash.
 
Very good point. As far as stability, one should do at least a 25%-30% weekly water change as you mentioned.
 
pH crash should only be a big concern in low KH (i.e., poorly buffered) water. If you keep nitrates in control (and 10-30 ppm is pretty good) then even acidification from biological processes shouldn't be a problem.

Unless the tank is heavily planted, if you can keep nitrates below 40, or better, 20 ppm, you should never experience pH crash. If you can keep nitrates down with 15% weekly changes, you're doing OK.

Jim
 
Thanks for the advice Jim.
 
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