SPS dying off one by one and I can’t figure out why

djryan2000 · Sep 18, 2023

The first 3 months all the SPS were all coloring up and developing growth tips. I had a mix of beginner acropora, montipora, stylophora, and birds nest. All aquacultured. About a month ago I had a nutrient swing where they went from ~.07 phosphate and 12 nitrate to 0 for both. I was trying to start nopox as I had some nuisance algae. I got nutrients back up to acceptable ranges over the course of a week and ever since I’m losing all my SPS one by one. Alkalinity is tested every 1-2 days and I haven’t picked up any swings.

A month out I’m still losing corals. Is this all a delayed response to the nutrient swing or am I missing something here? I can’t imagine that stylophora and birds nest are that sensitive. I’ve tried turning down the lights to ensure I’m not blasting them with too much PAR and it has not helped. Only other thing I’ve recently found was some surface rust on my inkbird temp probe. I don’t see any signs of parasites at night or fish going for the corals.

Parameters
Alk 7.7
Calcium 450
Mag 1300
Phosphate 0.14
Nitrate 7.8
pH 8.0
Salinity 1.026
System details - 47g tank, 10 or 20% water change weekly, lighting done by two radion XR15s, flow is by two MP10s on reef crest at 100%, nutrient export by a Tunze MAR and a reef octopus skimmer, 5 fish. Alk/Ca uptake is replenished with saturated kalkwasser dosed at night measured by hand. so a pretty standard setup.

Pod_01 · Sep 18, 2023

djryan2000 said:
The first 3 months all the SPS were all coloring up and developing growth tips. I had a mix of beginner acropora, montipora, stylophora, and birds nest. All aquacultured. About a month ago I had a nutrient swing where they went from ~.07 phosphate and 12 nitrate to 0 for both. I was trying to start nopox as I had some nuisance algae. I got nutrients back up to acceptable ranges over the course of a week and ever since I’m losing all my SPS one by one. Alkalinity is tested every 1-2 days and I haven’t picked up any swings.

A month out I’m still losing corals. Is this all a delayed response to the nutrient swing or am I missing something here? I can’t imagine that stylophora and birds nest are that sensitive. I’ve tried turning down the lights to ensure I’m not blasting them with too much PAR and it has not helped. Only other thing I’ve recently found was some surface rust on my inkbird temp probe. I don’t see any signs of parasites at night or fish going for the corals.

Parameters
Alk 7.7
Calcium 450
Mag 1300
Phosphate 0.14
Nitrate 7.8
pH 8.0
Salinity 1.026
System details - 47g tank, 10 or 20% water change weekly, lighting done by two radion XR15s, flow is by two MP10s on reef crest at 100%, nutrient export by a Tunze MAR and a reef octopus skimmer, 5 fish. Alk/Ca uptake is replenished with saturated kalkwasser dosed at night measured by hand. so a pretty standard setup.

Couple of comments.
From my experience birds nest and montipora are first ones to show decline if something is off.

Corals when they grow do need some food so perhaps reef roids or other good quality coral food would be beneficial. SPS do have lot of hungry mouths and NO3/PO4 is not necessary ideal diet for corals.

Also when they grow they do use/consume other things besides calcium or Alk. So you might want to consider some trace element dosing like Tropic Marin A and K.

Dosing kalk by hand might create might Alk spike that corals long term might not like. Maybe adding it to your top of water might reduce the spike. With SPS corals you want things as stable and perfect as possible.

Good luck,

kin_itsu · Sep 18, 2023

There is no picture upload.I have to guess the you had the same I had since the tank established around the three month.My nitrite and phosphate drop to 0 in three days causing the my frag lack of the nutrient and they died.Since I dose nitrite and phosphate they seem much better seeing some PE during the night.
I suggest turn down the skimmer and forget the algea problem for now.Try to save the left corals