Red Slime Algae/Cyanobacteria No Matter What I Do

[fishhead8]

I have had 2 different nano tanks and they have both had bad algae problems. In my old tank a biocube 16 I had used distilled water for top offs and used a premade salt mix at the start then switched to a 4 stage RO/DI machine with red sea coral pro salt and I had super bad cyanobacteria and used chemicleans cyanobacteria remover and it got rid of all it within a few days, but I then got super bad hair algae, which I was doing weekly 5 gallon water changes and would use a toothbrush to scrape all the algae off and remove as much as I could, and it would keep coming back week after week. A few weeks later and I just didn't have the motivation to keep removing everything from the tank and doing water changes for nothing, so I gave the fish to a local fish store. I have recently moved and decided to buy a tank and upgrade a little to a 25 gallon cube that has been up for a little over 1 1/2 years with a clownfish and royal gramma and quite a few corals that are doing very good, a overflow that has been drilled in and leads into 15 gallon sump with a filter sock, I'm not running anything currently other then the sock, a refugium with chaeto and a skimz sn127 protein skimmer, with some live rock and marine pure chunks also in the sump, and I have a BRS 4 stage and have been using instant oceans salt. I have had a very little amount of cyano and was doing my weekly water change and decided to do 7 gallons and removed all the visible algae from the sand and rocks. And within it day it has come back with about 4 times as much cyanobacteria on the sand mainly then before the water change. Is there something I'm missing and or doing wrong? I just don't want to have to restart again.

 

[Terry Mattson]

What are your phosphate and nitrate levels?

 

[fishhead8]

I lost my mini scoop for the Red Sea test kit but I tested 1 week and a half ago and I ordered some more but phosphate was zero and nitrate was 5

 

[Terry Mattson]

If your using api phosphate then it may not be giving you a usable reading. The ultra low range hanna phosphate checker is great. Typically a reading of .03 to .04 is good. Over that and could feed algae issues and some symptoms 0 is not good.

 

[William Mumford]

1 ml of hydrogen peroxide per gallon of water.

 

[fishhead8]

I use Red Sea not api I don’t know if that makes a difference, and I’m not trying to treat my tank I want to find the cause.