Pico Keeper
Premium Member
I'm fairly sure I know what happened but I want to bounce my theory off of a few people so I can learn from my mistakes.
Tank Background: I have a 90gallon that is mostly LPS, zoas, and a few montis. It's 50-days old for me but was established rock and system before I got it so I would consider it matured to at least the 1-year mark, frags are all mostly new 15-30 days..
Baseline Parameters:
100g total volume, 90g display, 20g water changes weekly with HW Reefer Salt
Decent sized refugium.
SG - 1.026
Alk - 9.0
Calc - 420
Magnesium - 1360
Nitrate - <1
Phosphate - This is what we're going to discuss..
The tank has a normal bioload, nothing crazy. I feed the fish and corals a normal amount, about 1 cube/day plus some Reef Chili or Reef Roids EOD. I also dose KZ Aminos, Sponge Power, Coral Vitalizer, and Pohls Extra about half of the recommended dosage as instructed for each.
Here's what happened.
The tank had zero algae, zero nitrate, but would test .1 Phosphate on the Hanna ULR Phosporus checker. I was unsure why the phosphates would be so high but it made me think we were outside the accurate range of the checker. Either way I wanted to get phosphates down so I bought a really powerful 300W Mars Hydro Grow Lamp to light my refugium with.
https://www.amazon.com/MarsHydro-Sp...TF8&qid=1501786383&sr=8-1&keywords=mars+hydro
It worked like a charm and got my phosphates down to .02 in the course of 10 days. It also completely filled my refugium with dense crazy amounts of chaeto. After those 10 days passed, I harvested about 90% of the chaeto and left 10% to seed. A few days later I saw the light spill from the lamp was causing some nuisance algaes to grow in my return chamber. Out of curiousity, I tested phosphates again and they had jumped back up to .09 which kinda freaked me out. The day I tested was water change day so I didnt worry too much as the tank looks phenomenal at the moment and I knew I was going to knock that number down by at least 20%.
Did my water change, life went on... Chaeto was growing extremely fast and maybe 6-7 days after initial harvest was getting pretty big again. BUT. It doesn't spin in the refugium, only the top gets light. So last night before bed, I grabbed the entire bed of chaeto and flipped it over so the darker part got some light too. I'm 75% sure flipping the chaeto caused my issue. The next morning everything looked great but my green monti cap had RTN'd a section over night. I tested phosphates on the Hanna ULR checker, it was 1ppb. I re-did the test to double check, this time it read 0. Uh oh.
My theory is that flipping the chaeto over last night caused a growth spike due to the intensity of the grow lamp. Sucked my phosphates to zero and caused the Monti to RTN. Just in case I pulled it out, dipped it in coral RX, inspected for nudis or other pests, but found absolutely nothing. I'm gonna clip away the dead section and im guessing it will bounce back. But I'm curious if my theory is valid. Can an overlit refugium and chaeto crush phosphate levels so low that SPS corals RTN overnight?
Here's the tank this morning, sump showing the light on, a pic of the RTN'd montipora cap and a small video I made for entertainment purposes.
https://youtu.be/h0br3AEPUhc
Tank Background: I have a 90gallon that is mostly LPS, zoas, and a few montis. It's 50-days old for me but was established rock and system before I got it so I would consider it matured to at least the 1-year mark, frags are all mostly new 15-30 days..
Baseline Parameters:
100g total volume, 90g display, 20g water changes weekly with HW Reefer Salt
Decent sized refugium.
SG - 1.026
Alk - 9.0
Calc - 420
Magnesium - 1360
Nitrate - <1
Phosphate - This is what we're going to discuss..
The tank has a normal bioload, nothing crazy. I feed the fish and corals a normal amount, about 1 cube/day plus some Reef Chili or Reef Roids EOD. I also dose KZ Aminos, Sponge Power, Coral Vitalizer, and Pohls Extra about half of the recommended dosage as instructed for each.
Here's what happened.
The tank had zero algae, zero nitrate, but would test .1 Phosphate on the Hanna ULR Phosporus checker. I was unsure why the phosphates would be so high but it made me think we were outside the accurate range of the checker. Either way I wanted to get phosphates down so I bought a really powerful 300W Mars Hydro Grow Lamp to light my refugium with.
https://www.amazon.com/MarsHydro-Sp...TF8&qid=1501786383&sr=8-1&keywords=mars+hydro
It worked like a charm and got my phosphates down to .02 in the course of 10 days. It also completely filled my refugium with dense crazy amounts of chaeto. After those 10 days passed, I harvested about 90% of the chaeto and left 10% to seed. A few days later I saw the light spill from the lamp was causing some nuisance algaes to grow in my return chamber. Out of curiousity, I tested phosphates again and they had jumped back up to .09 which kinda freaked me out. The day I tested was water change day so I didnt worry too much as the tank looks phenomenal at the moment and I knew I was going to knock that number down by at least 20%.
Did my water change, life went on... Chaeto was growing extremely fast and maybe 6-7 days after initial harvest was getting pretty big again. BUT. It doesn't spin in the refugium, only the top gets light. So last night before bed, I grabbed the entire bed of chaeto and flipped it over so the darker part got some light too. I'm 75% sure flipping the chaeto caused my issue. The next morning everything looked great but my green monti cap had RTN'd a section over night. I tested phosphates on the Hanna ULR checker, it was 1ppb. I re-did the test to double check, this time it read 0. Uh oh.
My theory is that flipping the chaeto over last night caused a growth spike due to the intensity of the grow lamp. Sucked my phosphates to zero and caused the Monti to RTN. Just in case I pulled it out, dipped it in coral RX, inspected for nudis or other pests, but found absolutely nothing. I'm gonna clip away the dead section and im guessing it will bounce back. But I'm curious if my theory is valid. Can an overlit refugium and chaeto crush phosphate levels so low that SPS corals RTN overnight?
Here's the tank this morning, sump showing the light on, a pic of the RTN'd montipora cap and a small video I made for entertainment purposes.
https://youtu.be/h0br3AEPUhc
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