I have green algae on my sand


Reefing newb
I have a 29 BC been running for about 10 months now. I have a ro/di unit with a TDS meter on it and I do A 5gal- 10 gal WC every week depending on how ambitious I feel. I have not changed my filters yet on my ro/di unit that I have had for about months. My meter reads 21 TDS going in and Zero coming out and it is very slow coming out (time to change I guess)

So my ? is Im starting to get green algae on my sand I have 2 clown fish I feed mysis shrimp 2 times a week and a couple of flakes I feed 2 times a week I have a skimmer on my BC and a cartridge filter. and i have about 40lbs of LR.
My levels are good and I also have a Kessil a 350 that i run 8 hr a day. What can I do to keep that algae at bay.

Thanks guys
It would help us more if you can post your water parameters and also some pictures. Nitrates and phosphates can be the cause of an algae bloom. If you say the water coming out reads zero on your TDS meter that means the water is not the problem, so it can be that maybe the flakes you are feeding your fish are feeding them. But this is just a guess.