Brown stringy algae.

JCTReefer · Feb 27, 2020

Any ideas what this stuff is? Reminds me of diatoms. Comes back within a day. Only in lit areas. Slimy and stringy on the wall and rocks. Bubbles on some of it. I’ve battled Dino’s. Cyano, you name it. Treated for cyano 4 months ago. Wiped clean. Now this crap. Torches have been retracted quite a bit. Nitrates 0, alk 8.0, calcium 400, phosphates .015ppm. Salinity 1.026. Magnesium 1400. Trying to get nitrates up a bit.

Lasse · Feb 28, 2020

IMO - both nitrate and PO4 has to go up. This type of algae (and Cyano/dino) is for me typical organisms that thrive in environment with low content of N and PO4 in the water column. What do you measure your PO4 with? The Hanna ULR checkers have an accuracy of ±0.02 ppm and the UR have ±0.04 ppm. IMO - the PO4 should be at least 0.05 if you use a working ULR checker or at least 0.07 ppm if you use an LR checker. If you use an ULR checker - a reading of 0.05 can be between 0.03 and 0.07 ppm if everything else is done the right way. If you use an LR checker - 0.07 means that you have between 0.03 and 0.11 ppm in reality - nothing else. IMO - below 0.03 ppm PO4 is a concentration that can cause different problems and if you have Cyano/Dino (or the one you show) - my first step is always to be sure that I´m over 0.03 ppm PO4 in the water column

Sincerely Lasse

JCTReefer · Feb 28, 2020

Thank you for the reply @Lasse !!! I use the Hanna ULR for checking PO4. Last reading was 5ppb Phosphorus so .015ppm Phospahte. I use the Nyos nitrate test kit for No3.. I'll get these numbers up slowly and see what happens! Thanks again for taking the time to respond!
Sincerely, Jeff