I have been battling an issue with what I can only visually diagnose as either spirulina, some combo of that and plain ole diatoms or just typical cyano. I have certain corals that have melted (Zoa’s) and a couple LPS I’ve owned for a long time that have withered away. Long story short I’ve gone after fixing this via discontinuing biopellets, I’ve dosed Dr Tim’s Eco Balance (probiotic) as well as Waste Away and Seachem stability for the last month or so along with a couple water changes, siphoning out what I can etc. Initially I suspected a phosphate deficiency as biopellets did not ever seem to take on this tank, but i did not have a reliable PO4 kit. I just acquired my Hanna ULR Phosphate checker and my DT came back after several tests at .09ppm
Further investigation revealed my RO/DI water is testing at .11ppm (distilled drinking water is coming back @ 0. A silicates test also revealed my source water as free of those. A handheld TDS pen shows 000.
I’ve done a bunch of research on this and some of the advice appears to be “don’t worry about it” as that amount of PO4 is incidental to the overall DT Numbers via top off, but on a 125 doing larger water changes @ a starting point of .10 PO4 makes lowering those challenging. I’m running GFO (HC - BRS) but I’m evaporating a little over a gallon per day, being replaced by .10 PO4 water. In other words, my top off/water changes have obviously been holding my PO4 around .09 in the DT (before I knew my source had PO4.)
I am trying to get the PO4 down to about .04-.05 to see what impact that has on the cyano and some of the other issues I’m having. Trying to narrow down the issue to stabilize things now that I have a better overal testing picture.
I’ve read several threads of people replacing all their RO/DI cartridges to no avail, adding another DI stage etc and I hate to just throw money blindly at something I’m not sure will resolve the issue.
Any thoughts on what the best course of action would be and any ideas what could be causing these issues? Here’s some other info:
Salinity: 35ppt
Temp: 79F
NO3: 5-7ppm
PO4: .09ppm
Alk: 8.5-9DKH
Calc: (high) 540
Mag: 1350
I have a pretty good bioload, run mechanical filtration, rox carbon, and have a Coral Box D500 skimmer (which I’m starting to think is slightly undersized for bioload.) and don’t feed super heavy.
After removing biopellets, my NO3 to my surprise didn’t really rise, it’s held steady around 5-10 for the last month or so. At this point I can only suspect the PO4 as the water parameters are relatively on point, but my corals are not thriving. Some are “ok” others, not so much.
Thanks for any brainstorming in advance!
Further investigation revealed my RO/DI water is testing at .11ppm (distilled drinking water is coming back @ 0. A silicates test also revealed my source water as free of those. A handheld TDS pen shows 000.
I’ve done a bunch of research on this and some of the advice appears to be “don’t worry about it” as that amount of PO4 is incidental to the overall DT Numbers via top off, but on a 125 doing larger water changes @ a starting point of .10 PO4 makes lowering those challenging. I’m running GFO (HC - BRS) but I’m evaporating a little over a gallon per day, being replaced by .10 PO4 water. In other words, my top off/water changes have obviously been holding my PO4 around .09 in the DT (before I knew my source had PO4.)
I am trying to get the PO4 down to about .04-.05 to see what impact that has on the cyano and some of the other issues I’m having. Trying to narrow down the issue to stabilize things now that I have a better overal testing picture.
I’ve read several threads of people replacing all their RO/DI cartridges to no avail, adding another DI stage etc and I hate to just throw money blindly at something I’m not sure will resolve the issue.
Any thoughts on what the best course of action would be and any ideas what could be causing these issues? Here’s some other info:
Salinity: 35ppt
Temp: 79F
NO3: 5-7ppm
PO4: .09ppm
Alk: 8.5-9DKH
Calc: (high) 540
Mag: 1350
I have a pretty good bioload, run mechanical filtration, rox carbon, and have a Coral Box D500 skimmer (which I’m starting to think is slightly undersized for bioload.) and don’t feed super heavy.
After removing biopellets, my NO3 to my surprise didn’t really rise, it’s held steady around 5-10 for the last month or so. At this point I can only suspect the PO4 as the water parameters are relatively on point, but my corals are not thriving. Some are “ok” others, not so much.
Thanks for any brainstorming in advance!