1. sunlight: yes some light in morning, but i have blocked out the sun hitting the tank with some background taped to the side(where sun hits).
2. photo period: 830-9pm 12-12.5 hours, 2x24watt 10k T5HO
3. substrate:black flourite
4. filter: rena xp2
5. plants: HC (hemianthus callitrichoides), dwarf 4 leaf clover(marsilea hirsuta)
6. water changes: 30% every 2 weeks. (~10gallons)
7. no other algae growing
8. I only vacume the very top bit, i do not push the siphon hose down into the substrate (as it disturbs my plants).
Does this help?

I've got a similar tank.

I found reducing the photoperiod cleared it up in about 2 weeks.

I currently have it at 5 hours / day. Any more and I get too much algae in one form or another.

Livestock: 5 guppies, 3 zebra snails.

Suspended algae in my reef was gone after a 100% block out of light for 3 full days. 100% dark! Dont even peek. Than a large water change. Idk what caused it but the black out worked and never had a problem since.

Green Water:

To clear this up I have found the best way to do that is as follows.

1: Do a bigger then normal water change
2: Complete black out. (No light, No peaking, No feeding) 3-4days
3: As soon as you introduce light after the blackout, Do another huge WC
4: Reduce your initial Photoperiod
5: Add some fast growing plants, I can't remember the names but when I had a Fresh water Planted tank I had plants that grew upwards to 1-1.5 inches a day!

This should all help reduce nutrients and green water algae suspended in your water column.

I remember reading many articles about the effects on Co2 on your planted ecosystems and how they effect all your current levels and help balance everything.

You should look at adding a Co2 system into your tank DIY, or Tank if you want to get a little more technical in your system.

Thanks hazratty, the green water has since lightened up. I can actually see the back wall.....yay! I've thought of uv, but I'm dragging my feet I really wanted this tank to be ultra low maintenance. Co2 would be ok but again more crap to tinker with. I will leave all the tinkering for my reef. Reducing my photo period has helped I think. It's the only thing I have done to the tank since the pea soup outbreak. Thanks for the advice. Once this water is crystal clear I will post on pic....at least my plants are filling in nicely.

Finally the green water is 100% gone....only took two months. But wow my little planted tank is cool again, i almost shut it down. Sure glad i didn't. like watching all the lil shrimp and the plants fill in. Thanks to all for their advice!:biggrin:

now that its straightened itself out it should be easy to keep up. i used ceramic beads and filter sheets and carbon wc once a week. good luck:rocol: