Unhappy plants

[Poustic]

Two months ago I put some Phos-Zorb into my canister filter, replaced a flora-glo tube with a power-glo tube, reduced liquid fertilization, and started adding AP root tabs, in an attempt to control some of the black algae that is expanding on some plants and on my mopani wood.  Two months later, many plants are starting to lose leaves, growing roots everywhere along the stems, and don't look great overall.  I've recently started dosing more liquid fertilizer (Flourish complete + iron + potassium) but it didn't help.  My CO2 injection is stable.  What would be the best explanation?  Phosphate deficiency, or wrong combination of tubes?  I have 2 power-glo's and 2 aqua-glo's.

I removed the Phos-Zorb two days ago, and am waiting to see if anything good happens.  Should I consider adding phosphate, or just wait and see?  What is the best way to increase phosphates without promoting algae growth?   :?:

[ekim]

Poustic,
Yes the Phos-Zorb is one of your problems!
Plants need light, CO2 & N-P-K and traces to live!

Your BBA is probably due to a lower amount of CO2 than the plants need under higher light levels.

Cutting off your ferts will only harm the plants more and give algae a foot hold.

Hope this helps.

[Poustic]

Thanks for the reply...  

It looks like I have enough K, but not enough P (and N).  Good news is plants seem to have stabilized since I removed the Phos-Zorb.

I am currently using Flourish "Comprehensive" for general + trace elements, and some additional Flourish "Iron" and "Potassium" as needed.  Would Flourish "Nitrogen" and "Phosphorus" do a good job for the missing N and P, without stimulating the black brush algae?  or are there better choices, other than having a better substrate?  

CO2 looks OK according to chart, I am putting enough to keep pH=6.5 at KH=2.