With 40 ppm nitrate concentration, its no surprise HITH is starting ro rear its ugly head.
P Bass come from waters where nitrate concentration is in the single digits.
If it were me, I'd start doubling my water change routine to 80% per week as a normal routine.
and if that's difficult , I'd start doing 40% twice per week.
And expect to double that once they get much bigger, these fish start pumping out waste by leaps and bounds as they grow, so water changes need to be ramped up to compensate for the added output.
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