I read something someplace about keeping co2/ferts/light balanced, and that an excess of any will cause problems. I was of the mind that co2 *always* should be kept at the max possible (before the fish start to act wierd/sluggish/gasp).
Am I incorrect? will high co2 combined with relatively lean ferts/light timers CAUSE algae?
Everything I've read and experienced suggests this is correct.
Not trying to sound contradictory, but...
read and experienced suggest this is not
Everyone talks about balance, but I think that confuses people into thinking there is a magic formula. There's not. Your tank needs enough
nutrients, and enough
light, and enough
If you dose one of the prescribed methods of dosing, like EI, PPS, or PMDD, your tank has enough nutrients. That eliminates one of the variables. From there all you've got to worry about are light and co2. If you've got livestock(which in your case you don't) then you have an upper limit on how much co2 you can pump into the tank. That means you also have an upper limit on how much light should be over the tank. However, no livestock means no co2 limit, which means no light limit...to some degree. At some point, no matter how much co2 you have, you can have enough light that you still have algae.
For example, I've run a tank without fish, dosing EI with AS as substrate, and jacked my co2 way up (50-60 ppm) and used 6wpg over a 17g tank. No algae, great growth. But, the moment I let that co2 drop...algae city.
However, in my experience, not enough nutrients combined with enough light and enough co2 does result in algae issues.