Glossostigma carpet, help!

[204sixspd]

Hey all,

I started this glosso carpet from seed, and have been growing it for about 3 months. It has turned yellow, but strangely the plants in the shade of the rocks are green. Is this a lighting issue ? I have had some brown algae and green algae in the tank, and have been trying to keep that clean. This is my first real attempt at a planted tank. I have been monitoring ammonia, ph, nitrate and nitrite and all have been ok.

Setup:
30 Gallon
Flourite Black
1500lph canister filter
50% water changes weekly
Dosing with flourish at each water change
2bps co2
23*C water temp
50w led flood light 6500k 8 inches above water
Black granite rocks

Can anyone give me some suggestions as to what to try next ? I am currently running the light 12 hours a day. I used to have 2 flood lights but cut back to one. Haven't noticed any improvements. The plants still seem to be alive, just not green.

Thanks

 

[Dallascowboys16]

Yellowing of leaves can be an iron deficiency, but also potentially a nitrogen deficiency. Flourish is a fine fertilizer for lower light applications, but I would recommend you look into EI dosing. GLA sells a really good cheap starter pack. It's pretty easy to get the hang of. The whole idea with EI dosing is that you always have adequate nutrients in the tank and reset once a week with a large water change. With higher tech setups it is much easier than trying to dial in how much flourish to dose.