Bright colors on the edge of sandbed

Twaves18 · Nov 13, 2020

I have a 15 gal nano tank, been up and running for about 5 months now. Ive been seeing new and consistent algae growth since month 3. About the same time I noticed a small amount of these bright colors and didnt think much of it. 2 months later the colors range from bright red, to cyan, to a greenish yellow, covering most of the perimeter of my sand bed. The last couple of days this coloration has extended above the sand bed. I am concerned that this may be detrimental to my tank, first believing it to be the cause of trapped air (it is not). I have no clue what this is, could it cyano? dyno? or some type of algae? If you have an idea please lmk, so far my tank seems to be doing perfectly fine with this unknown entity.

Salinity= 1.24
Ammonia= 0
Nitrites= 0
Nitrates= 5-15 (bad testing kit)
Temp= 79 F

Webslinger · Nov 13, 2020

phosphates? It’s cyano. Completely normal.

NeonRabbit221B · Nov 13, 2020

+1 for cyano

Bump up CUC and reduce nutrients.

brandon429 · Nov 13, 2020

my bed has little areas of that in the back, not a big deal. you are allowed to clean it any time you want, or let it ride to fuller levels and then do big catchup cleanings, that's not harmful above till its 80% of your sandbed, clean before then.

it doesnt become toxic even at 80% levels but by that time of no cleaning, any part of the bed that accidentally gets stirred up with a rock slide or a powerhead detachment risks kicking up the waste bigtime, left totally alone the bed w probably run years it just becomes an access risk if we dont find a cleaning balance in nanos.

schuby · Nov 13, 2020

Going up the side, it's probably expected cyano as your tank starts to mature.

I think that nitrate-fixing bacteria grows in the sand. The side of my sand has burgundy and other colors below the surface, only visible from the side. I believe it to be part of a healthy tank's biome.