Green algae on glass and rocks


New member

I'm running a reef tank in a Innovative Marine 20 gallon since June 29 2019 and I'm starting to have green algae.
My nitrate and phosphate are both at 0.

I have the stock return pump, a MP10 and a IM Nuvoskim DC Protein Skimmer Desktop.
My filtration is, Chemi pure blue and purigen into 2 media basket on each side with some AquaForest life bio fil and 2 filter pad.

I have 2 AI Prime HD at 8 inch of the water level.
What can be the cause of that because this is the first time I'm having green algae like this.

Here some photos of the tank and my light schedule.

Thank you.


New member
What is your CUC consist of? Looks like green film algae. What test kits you using?

I would get some snails(Dwarf Ceriths, Nerites, and Astraea good for these)


New member
The algae is sucking up the NO3 & PO4 and a balance will come about as the tank matures. I would continue what your doing with a bit of a reduction in food. I have had success with algae turf scrubbers and weekly water changes on an overcrowded 13.5.


Saltwater Addict
Get a scrapper magnet for the glass and some extra snails for the rocks. Like you mentioned it will work itself out as the tank matures


New member
Bwahahahha that's nothing. You should have seen my tank during its first 5-6 months. Was covered so bad I almost took down. But then it just started to die off. I didn't do anything bUT feed smaller amounts to my fish. And it all turned purple on my rocks and glass and boom mature-is tank.just let it do its thing


New member
Also.I'd cut back on adding coral. Once thar algae dies off it will spike the tank. Some of those corals you have are sensitive to change. Esp the BTA. It can handle it but doesn't mean it's immune system will be able to handle the flucations in your system right now.... take it slow...... when you feel like it's time for coral wait another 2 months then add some. Remember to test your water 1 once a week.


New member
Make sure you've got good test kits as well. But patience patience in this hobby, and lots of snails.

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