Cyano and maybe something else

[Docdiggy]

Yes, I don't know what nitrates are. Only test i ever tried was api for that. Always read 0.

 

[Docdiggy]

I also added a larger skimmer. I'm not a newb at this, I just never tested these things because I've always had good growth and decent color. It's made life much easier putting my sump in the other room for maintenance and water volume.

 

[fishbox]

I'd say that's your next step. Test your trates. As mentioned above, low N or P, or an imbalance of N or P can cause algae issues. On top of that you don't really wanna be trying to fix things without knowing those numbers. Especially is that fix can alter those numbers.
Do you deep clean your sand with a vac?

 

[Docdiggy]

I do that every water change. It's a shallow bed. Looks great for a couple days. I typically only do 5g a week so my other numbers don't fluctuate much.

 

[fishbox]

Okay I was just curious because I'm kind of going through the same issue and I never did that but I was also running without a skimmer. I just started deep cleaning my sand bed so I hope that helps. But I also just built my sump and purchased a skimmer which I hope to have online within the next week or two.

 

[Docdiggy]

I had an undersized skimmer for a long time. I added a vertex omega 150. I skim a tad on the wet side and I need to clean it every 3 days now. It stinks my whole basement out when I clean it in the bathroom. What an improvement.

 

[fishbox]

Ohh mine's gonna be horrible! I started this tank almost a year ago and besides water changes, there's been no other export. No skimmer, no reactors, not even a HOB filter. And again I never cleaned the sand till recently. I do have test kits for n and P but I couldn't tell you what they are because they are so high they don't even register on the test kits LOL