foam buble on top of my aquarium

[alexlab79]

hello, i have foam on top of my aquarium?!

my aquarium is an hagen 77G
Many Filter on it:

40-60 aquatech filter from my old aquarium
internal Fluval 3+ for water circulation
50 gallon aquaclear
And since 2 mounth i have installed and sump with and ats.
The sump is gravity feed by diy overflow of 1" and the return pump is 600gph a zero elevation
the system seem to run pretty good. The Ats is drived by an pump of 400gph. The screen is 9x8 in size and illuminated by 2 cf of 23watts. The first 1 1/2 month i clean the screen 2X by week. Big hairly algua on screen and on side of sump(i need reflector) but now the grow is very slow on screen(weekly clean or a little more) and no algua on sump or just a little and the plant of my aquarium fade in color(turn yellow or degrade)

i have changed the light for test no change in grow in the ats and the pump of ats run very good(good pressure)
it's seems to be good but since 1 week i have noticed little bubble or foam at the top of my aquarium on each side...i read on internet and bubble foam is sign of high ammoniac and nitrate...i don't have test..but i am little bit worried...my fish seems to be in good health but i don't want desaster in my aquarium...at your opinion...whats is this problem??? only not degraded organic pollution? thanks for fast reply.

P.S scuse for my english.. i speak in french!

[SantaMonica]

I think foam is from some oily food that you fed, although others may have different ideas. It should not hurt anything, and after all, is just food.

Your plant is probably dying because the scrubber is so strong. If you want, remove one bulb, and the scrubber will grow less.