I gather from all the discussion of "limiting factors" something must have
recently come into short supply in my aquarium, and I know I'm going to
have to experiment, but I was wondering where to start. Something has
changed over the last couple of weeks. Assuming these are related, this is
the order of events (1) the hornwort started to get a reddish brown tint at
the crowns (2) all of the new growth on one of the swords is yellowish, on
the other it's more of a pale (whitish) green (3) my foolproof Java Fern
has started to get yellow tips on its leaves. The anacharis and especially
the moneywort (that's how it was sold, I assume from Rataj that it's some
sort of bacopa) are still growing rapidly.
I know the setup is not ideal . . . and I'm working on a new tank, but with
my budget these things take a lot of time. Light is inadequate (around
1.4w/g). There is a UGF. The tank is a little overstocked with fish. But
the plants were surviving with these before. The only thing I can think of
that has changed is that I switched to RO water (to try to cut down on the
phosphates I was adding to the tank). I'm having a bit of difficulty
bringing the KH up without bringing the pH too high, and this will only get
worse now that I have heard that the silicates in Acid Buffer are bad.
Anyway, I also have a yeast CO2 on the tank, but have had it for months--it
helped at first. I add a little Flourish 2x/week. Is it time for me to
buy some of the pricier test kits, like iron and phosphates? Or should I
try something else first?