Weird weird white circular spots on my tank wall. Help needed

[seudzar]

Hi All,

Recently I notice this white circular stuff growing on my tank algae wall. I do not have any idea what it is. Thus i am posting it here for more advise.

Please see the below photos:

White circular spots on wall


Full tank shot



This is a Sulawesi Tank setup.

The size of the tank is 50cm x 34cm x 34cm.
Filter: Gex Slim L with sponge at the inlet, filter media are Seachem Matrix and Biohomme and there is a double air sponge filter. Light is 15 watt LED that is turned on more than 10 hours to promote algae grow for the sulawesi shrimps to feed on. Feeding is very minimum.

pH is 8.2, TDS is 168.

Please advise, if you need more tank information, please ask i will provide more.

I seriously think the nitrate and nitrite is not high.

[Xksinz]

I had that before. But not so serious. Should be fungus due to overfeeding or some fish died and rotting somewhere.

[seudzar]

I had that before. But not so serious. Should be fungus due to overfeeding or some fish died and rotting somewhere.

Hi Xksinz, thank you for replying my post. I did water change and reduce feeding. The white circular spot are reducing at very slow rate. Thanks. Will continue to monitoring and do constant water change