Happy'Cam'per wrote:
"Iain Miller" wrote in message
...

High phosphates are a known cause of Algae. To get rid of Algae you
need
to get your plants growing better - this will starve the algae out.

Iain, PO4 will not cause algae, neither will KH. Bad conditions for
plants
is what causes algae. If you have good lights, co2 and are
fertilising then
plants flourish, take away just one of the elements that they need
(like
PO4) and you will get algae.

IMO, The OP needs to add some CO2 & NO3.

I'll second the above regarding PO4. My plant tank is only about 2.5
months old, and save for some greenwater at the beginning and trace
amounts of green-spot algae now, the tank has been algae-free - and I
intentionally attain PO4 levels 2ppm! (My tapwater is ~3ppm in PO4)

People like Tom Barr, et al., dose plenty of PO4. If the rest of the
tank is in good shape, that doesn't present a problem.

I'll second the above with respect to KH, too, assuming no CO2
injection. Simply put, the only thing that affects, if one is not
using CO2, is the pH. And that's just not a big deal for algae.

KH can possibly matter if one *is* using CO2, though. Then, KH
determines [CO2] at a given pH - which pH one maintains with the
controller, etc. Since we know we want a given pH (for our fish) and a
given [CO2] (for our plants) when using CO2 injection all one has to do
is choose an appropriate KH. See the CO2/KH/pH charts. You probably
don't want to have lots of (even balanced) nutrients but insuffifient
CO2 - so KH must be monitored.

Still, I think it is fair to say that KH, per se, is not a concern of
the plants (including algae).


--Trapper