I have a 110gal extra tall tank. It's dimensions are 48" wide by 30" high by 18" front to back.
I've got a light fixture with four 48" T5HO. The bulbs can be turned on / off in pairs. I've been running a 10hr photo-period.
So if my math is correct, with one pair of bulbs on I've got 108w which is 1wpg for a "low" light level. But before CO2 every plant in the tank was covered with black algae. Now I add CO2 and the algae seems to be kept at bay. Plants aren't growing gang-busters but they do grow. Now, if I turn on the second pair of bulbs for 216w, for 2wpg (should be medium light, right?) I seem to notice the black slime algae growing on the leaves & rocks again.
My ferts are perfect- I've got access to lab grade testing equipment. I've got the CO2 cranked up to just a little less then fish gasping at the surface and I'm adding twice the recommended dose of Florin Axis (liquid carbon supplement, not the same as excel.) My pump turns the tank volume over about 7 times an hour.
The only thing I can think to question is that there's something with these T5HO bulbs that put out so much light that the wpg guide doesn't hold up.
Thoughts?
I've got a light fixture with four 48" T5HO. The bulbs can be turned on / off in pairs. I've been running a 10hr photo-period.
So if my math is correct, with one pair of bulbs on I've got 108w which is 1wpg for a "low" light level. But before CO2 every plant in the tank was covered with black algae. Now I add CO2 and the algae seems to be kept at bay. Plants aren't growing gang-busters but they do grow. Now, if I turn on the second pair of bulbs for 216w, for 2wpg (should be medium light, right?) I seem to notice the black slime algae growing on the leaves & rocks again.
My ferts are perfect- I've got access to lab grade testing equipment. I've got the CO2 cranked up to just a little less then fish gasping at the surface and I'm adding twice the recommended dose of Florin Axis (liquid carbon supplement, not the same as excel.) My pump turns the tank volume over about 7 times an hour.
The only thing I can think to question is that there's something with these T5HO bulbs that put out so much light that the wpg guide doesn't hold up.
Thoughts?
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