Green Algae on Glass

sg1.025 · Jul 21, 2024

I've recently began to notice that I daily begin to get some growth of green algae on the front panel of my tank. My tank is an older Red Sea Max 250. I clean it daily, but it continues to return. I change 10 gallons of water every Friday and tops off daily as it's an open top. Most of my water parameters are within range, based on what I read within some of our forums.

My tank inhabitants:
2 Pajama Cardinal Fish
2 Clowns
1 Bursa Trigger
1 Valentini puffer
1 Lawnmower Blenny
small cleanup crew

My tank has a very small amount of sand, probably about 1/2" within 1 square foot. I have a ton of coraline algae growing. Lights are 2 Kessil A360x and are on for about 8hrs per day. I have a Red Sea Wave 25 also running several hours a day.

I have some coral which all seem to be doing well also.

My water parameters below:
(Hanna Tests, Salifert, Fluval)
Temp: 78.2F
Salinity: 1.025
Ph: 7.9
Ammonia: .04 ppm
Nitrate: 9.10 ppm
Alkalinity: 8 dKH
Phosphate: .16 ppm
Calcium: 455 ppm
Magnesium: 1300 ppm
Silica: 0
Nitrite: 0 ppm

Chiller set at 78.5 degrees

I've been told that a Nitrate of 9-15 ppm is ok, and all has thrived, but only until recently (2-3 weeks ago) did the green window algae pop up. My room does face south, with one tinted window allowing sunlight in and hitting the tank on the north wall of my office.

Any thoughts on how to control this are welcome. Some flames are tolerable!

Formulator · Jul 21, 2024

LOL! Its normal. There’s nothing you can do about it and everyone has it. Get a magnetic scraper and manage it as part of your normal routine. I have to clean mine every 2-3 days. Only takes a few minutes. Just be careful not to get sand in the scraper because it will scratch your glass.

sg1.025 · Jul 21, 2024

Formulator said:
LOL! Its normal. There’s nothing you can do about it and everyone has it. Get a magnetic scraper and manage it as part of your normal routine. I have to clean mine every 2-3 days. Only takes a few minutes. Just be careful not to get sand in the scraper because it will scratch your glass.

Thanks!!! Perhaps it was there daily and i didn't notice it. But yes... i do have a "thingy" (new technical term) to scrub off the algae from the glass... with extra precaution to avoid any sand particles within the scrubber.

Formulator · Jul 21, 2024

sg1.025 said:
Thanks!!! Perhaps it was there daily and i didn't notice it. But yes... i do have a "thingy" (new technical term) to scrub off the algae from the glass... with extra precaution to avoid any sand particles within the scrubber.

It tends to come with tank maturity in my experience. You might be able to tweak the nitrogen and phosphate levels to reduce how often you need to scrape, but your levels are really good so I don’t know if I would mess with it. I do find mine ebbs and flows with the seasons and just this week my own tank near a southern facing window has increased algae on the glass.