Green stuff on and in sand?

[Noahspapa]

Hello. Ive attached some photos of the sand in my 120P tank. There is some sort of green showing on the surface of the sand but also along the side glass. I did put quite a few flourish root tabs in when i set this up approx. 2 months ago and I’m wondering if it might just be the root tabs leeching out? Please take a look and let me know what you think. Thank you.

 

[Naturescapes_Rocco]

To my eyes, that's cyanobacteria.
If you test your macros, what are your NO3 and PO4 levels?

 

[Noahspapa]

Tested just now, photo bellow. I think the nitrate is around 5 and the phosphate is somewhere between 2-5. I use APT3 to fertilize.

 

[Naturescapes_Rocco]

Sounds pretty similar to what I talk about here. Lots of PO4 available, maybe not so much NO3.
To treat it, I'd spot dose it with either 3% H2O2 , or APT Fix, and siphon it out. If that isn't enough, you may need to use Ultralife cyano remover, which works amazingly well.

My recommendation would be to keep your NO3 a bit higher, more like 10ppm. Chances might be that it's dipping too low throughout the week for plant demand, but that's just my thought. I've used this method to treat Cyanobacteria for about 5 years, although I haven't seen a hint of cyanobacteria since I started running more NO3 in my water column. Been about a year in both big tanks without it.

 

[Noahspapa]

Another thing thats strange to me is two days in a row I notice that in the morning when the light turns on i don’t see the green on the surface of the sand, but it does reappear over the next hour.

 

[Mr.Shenanagins]

If it’s not on the plants but sand only, I think I’d just siphon out the affected sand. If it reappears then go the chemical route but I agree with @Naturescapes_Rocco it appears to be a small cyano breakout

 

[Noahspapa]

It is on the sand only. I ordered some nitrogen to add - will receive that in a couple days. Did a couple water changes. For the most part the plants and fish are very healthy and growing. Based on various inputs i had previously purchased a anti-Cyano product to have in case of a problem. I opened that up and read the instructions yesterday. It said to add airstones in advance so i added two yesterday afternoon. Then early this morning i added the chemical (blue green slime remover). I’ve been hesitant to siphon and remove the sand as I’m afraid to disturb the crypt nurii that seem to be growing well in the sand. I guess I'm just going to have to do that.

 

[Naturescapes_Rocco]

You won't regret using that blue-green slime remover! I've used it many times without any adverse effects. Cyano just melted away without a trace after 5 days.

 

[Noahspapa]

Thanks for the inputs folks! This is my fifth tank and first instance of cyano. I still wonder if i caused this by putting root tabs in the sand.

 

[Noahspapa]

Its only my second tank with sand.