the only thing I never understood is if it's a problem with low
nitrates why change the water then?

if you're getting rid of spores, that's futile because of the high
turnover of the bacteria anyway.

as i understand it old water=more nitrates, as long as you feed the
fish more, and got a well-cycled tank to convert ammonia.

been dealing with this problem, the whole time with my 4 year old
planted. the funny thing is when I stopped changing water as
frequently, the bga change from the dense black mat, to a more
manageable brown scum (still smells the same with that swampy odor), it
never goes away completely with maramycin.

realistically, your goal has to be to achieve some acceptable balance
with removeable or mimimal amounts. the high phos that drives it is
largely from the tap water anyway (if you do frequent changes), so the
only way to get low phos without using chems is to move to a different
town.

you just got to work with the cards you've been dealt.

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