Hi there

Ditch one of your tubes, 3.5 watts per gallon is a tad on the bright
side. Try 2 WPG or near to there. Your co2 is not keeping up (20ppm)
with this ammount of light. Maybe cut an hour out of the photo period
aswell.

Ditch the activated carbon aswell, no use for it in a planted tank.
You might be TOO RELIGIOUS with your maintenance routine , Are you
adding Nitrates back to the tank after water changes? If your N is
0-5ppm then your plants are starving. There is a relationship between
N & P, I would say that your Nitrates are being used up too quickly
therefore leaving the available Phosphate to float around the water
column...

IME Root stix are a disaster, this may be adding to the phosphate
levels you report. Try and vacuum some of them out. If your tank is
only 6 weeks old you might want to give it a bit of time until you
have some mulm build up before seeing any good signs in the plants!
You will have to start dosing Macro ferts in the water column as I
think your gravel may still be a bit sterile for plants to inhabit
happily.

You must start adding ferts asap, your plants are starving.
Go to the pharmacy/drug store/chemist and buy the following:
But before adding ferts, ALWAYS make sure that your co2 levels are
high and are stable. Add another bottle if you have to, according to
Tom Barr you want to shoot for about 30ppm in the morning and try and
keep it there, if you are at 20ppm in the evening this would be ok.
Salt Petre (Pottassium Nitrate or KNO3) dose 1 level teaspoon twice a
week. This will take care of Pottassium aswell as Nitrates. No-Salt
contains Pottassium Chloride and could be added as an extra dose but
probably not necessary.
You can get fleet enema as a phosphate source (when your levels come
down), dose 3 drops twice weekly.
You can use Epsom salts as a Magnesium source, Or dolomite
pills/powder as a calcium & Magnesium source at the correct ratios.
Im not sure about the dosing quantity for this one, I let the plants
indicate a calcium deficiency by looking at the leaves on Hygro
Polysperma, they get "wrinkled".
Of course not to forget your micro ferts which can be bought at any
LFS, take your pick, I've used Kent and Sera ferts and they seem to
work well!

Hows that for a long winded post

Cam, I had to thank you for that explanation... I've saved it because I want
to use it later, it will add to my pile of useful info I've collected over
the years...

and Nemo, you're post has also been saved....Thanks.

--
RedForeman ©®
Sorry about the troll, the ball is rolling there....