The question is which setup is minimally needed to grow carpeting plants like HC without c02 or in a non-c02 tank?
In my non-CO2 tanks, the HC really grows thick in about 60 umols/m2/s of light (PAR) - and that's measured at the bottom of the tank where the HC is growing. So in the graphics above, any setup that shows PAR values in a range of 60-70 should be "sufficient" light. It doesn't mean you can't go higher. But in going higher, you may be over driving your soil's ability to provide enough nutrients. And even if you dose the water column, the higher light will start to give algae a good environment in which to grow.
In my non-CO2 tank with an average of 60-80 umols/m2/sec, I never change the water, I dose nitrates-phosphates-traces each twice a week, I have a soil substrate, and I don't have algae buildup anywhere in the tank.
But that wasn't always the case... During the first two months I had several patches of different kinds of algae. But I just let them run their course without attempting to fight them, and then did a removal when they seemed to be dying off. It's never come back. Also added snails and 5 amano shrimp... I was amazed at how they started to clean up the tank.
Did any of the above answer your question about the minimal setup required?
Jeremy Squires, Toronto, ON
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