IUfan
Member
Carbon dosing has been associated with RTN in sensitive corals. Do you use a lot of pellets?
Rapid changes in the phosphate level can harm some corals also. When you change GFO does the phosphate level change quickly?
+1
I had a similar issue, would be all good and then would suddenly either have browning or bleaching occur.
I believe Po4 and light intensity have a direct correlation to one and other. Higher Po4 requires higher light, lower po4 less light.
At the end of the GFO life your light intensity may be perfect for the level of Po4 then you renew the GFO, it sucks out all the Po4 and light is too strong, corals bleach.
I had this occur, so then I would try less light, only to have the corals brown at the end of the GFO light. So then I increased light back up, and bleaching occurred.
Conclusion is: I stopped using GFO, let Po4 creep up to 0.1 and run my lights at a higher intensity. Params stay more stable. And tank has never looked healthier. SPS are growing like weeds with great color and PE. = happy reefing.