Need help ID and treatment

Tham121988 · Dec 5, 2019

I have a 7 gallon pico with a 2.5 gal refugium that's been running for over a year. All of a sudden I started getting some yellow patches of algae. I siphoned this up and it has come back and continues to get worse. All parameters are normal. Nitrite 0, Ammonia 0, Nitrate 0, pH 8.3, mag and calcium within acceptable ranges. Temp is 77.7.

Hemmdog · Dec 5, 2019

Feed more high quality food, 0 nitrate is way too low.

Auquanut · Dec 5, 2019

I'm going to agree with @Hemmdog on this one. Do you have any fish in this tank? CUC? A 7 gallon pico with no nitrate seems amazing to me.

lapin · Dec 5, 2019

If it blows of easy and comes back the next day with lights on it might be cyano. It looks green to me. Cyano comes in many colors. It likes light and no flow.

Tham121988 · Dec 6, 2019

Auquanut said:
I'm going to agree with @Hemmdog on this one. Do you have any fish in this tank? CUC? A 7 gallon pico with no nitrate seems amazing to me.

I have a watchman goby and pistol shrimp. Some porcelain crabs. Cleanup crew.

Tham121988 · Dec 6, 2019

Its mustard yellow. I just have never seen an algae like this. So what do I need to do? Any ideas?

Tham121988 · Dec 6, 2019

Hemmdog said:
Feed more high quality food, 0 nitrate is way too low.

I'm going to get a new test kit and check again. Also going to get the LFS to check to make sure those readings are right.

BloopFish · Dec 6, 2019

We need to know more about the texture and consistency to properly identify it. If it is goopy, mats and it blows off easily in sheets like lapin describes it's likely diatoms. If it creates strings with bubbles trapped in it it could be dinos (which I don't think it is from the pics). Or it could just be diatoms, which goes away with time.
It could be that your nitrates are being used so much and so fast by the algae that it is undetectable, especially if you only feed lightly. Your tank is also old enough to be denitrifying stuff by now, so it may just be so low because you aren't feeding much. Either that or your refugium is sucking it up so well. Could you describe your refugium?

Tham121988 · Dec 6, 2019

lapin said:
If it blows of easy and comes back the next day with lights on it might be cyano. It looks green to me. Cyano comes in many colors. It likes light and no flow.

I thought cyano produced gas bubbles. This has none.

Tham121988 · Dec 6, 2019

BloopFish said:
We need to know more about the texture and consistency to properly identify it. If it is goopy, mats and it blows off easily in sheets like lapin describes it's likely diatoms. If it creates strings with bubbles trapped in it it could be dinos (which I don't think it is from the pics). Or it could just be diatoms, which goes away with time.
It could be that your nitrates are being used so much and so fast by the algae that it is undetectable, especially if you only feed lightly. Your tank is also old enough to be denitrifying stuff by now, so it may just be so low because you aren't feeding much. Either that or your refugium is sucking it up so well. Could you describe your refugium?

I have a bare bottom refugium with tonnnnnns of pods and ghost shrimp. Chaeto fills it. 2 powerheads that keep it spinning. Then a kessil refugium light on top. Grows like crazy.