SPS corals not doing well

[JACKS REEF]

Ive had my 60 gallon cube tank for a while now probably about 5 years and its had its ups and downs. Been battling algae for a while but finally it’s starting to reside. Every few days if i don’t clean the glass i will get diatoms but thats not the root of the issue. My LPS corals seem to be doing okay my frogspawns, hammers, torches, and goniporas all look somewhat happy. Recently i put in a green stylophora and it opened up well but for about 1.5 months i saw absolutely no growth, and now the polyp's are not really out. I added a red montipora digi to my tank as well and it did not open up at all, so I had to move it to my other system. My cyphastrea half of the coral RTN’d but seems to be regaining color. My hollywood stunner seems to be doing well and is growing slowly. My favia colony is dull on color. Im just confused on why some corals seem to be doing well while others are not at all. My lighting is a radion g5 blue, and i run a skimmer, and a bio pellet reactor. My lighting schedule is running at 75% with my whites running for about 4 hours and my blues running about 5-6. Im dosing calcium, alk, and mag. My current parameters are

7/10/25

DKH 9.6

Calcium 360

Mag 1095

Nitrates 2 ppm


7/19/25

DKH 9.5

Calcium 350

MAG 1335

N03 6 ppm

 

[Mr. Mojo Rising]

Have you ever rented a par meter? do you have the xr15 or xr30? I'm thinking the lights might be low, also its a short photoperiod, I run my lights for 10 hours.

It might also be the low nitrate level, and you have a high alk, so its like pushing the coral to grow faster but not giving the nutrients it needs to grow.

 

[commod0re]

350 Calcium is way low for SPS isn’t it?

 

[tbrown]

What are your phosphates?

 

[billyocean]

Compare the water of the two tanks...could also be lighting. I may lean towards making sure there are no white bugs/red bugs etc.

 

[JACKS REEF]

Have you ever rented a par meter? do you have the xr15 or xr30? I'm thinking the lights might be low, also its a short photoperiod, I run my lights for 10 hours.

It might also be the low nitrate level, and you have a high alk, so its like pushing the coral to grow faster but not giving the nutrients it needs to grow.

Xr30 lights

 

[JACKS REEF]

What are your phosphates?

Have you ever rented a par meter? do you have the xr15 or xr30? I'm thinking the lights might be low, also its a short photoperiod, I run my lights for 10 hours.

It might also be the low nitrate level, and you have a high alk, so its like pushing the coral to grow faster but not giving the nutrients it needs to grow.

my lighting runs for 12 hours with 30 minute ramping periods.

 

[Fish Fan]

Do you know what your phosphate is? Your nitrate is a quite low, which is making me think your phosphate is bottomed out to zero.

 

[JACKS REEF]

Do you know what your phosphate is? Your nitrate is a quite low, which is making me think your phosphate is bottomed out to zero.

Just tested my phosphates using a salifert test. Water in the test sample looks close to 0. But I dont know the accuracy of this test.

 

[Fish Fan]

Just tested my phosphates using a salifert test. Water in the test sample looks close to 0. But I dont know the accuracy of this test.

The Salifert tests are considered fairly accurate if performed as instructed. This may be your problem here, you don't want zero phosphate and nearly zero nitrate, that's not good for coral health.

 

[JACKS REEF]

The Salifert tests are considered fairly accurate if performed as instructed. This may be your problem here, you don't want zero phosphate and nearly zero nitrate, that's not good for coral health.

I have neophosphates should i dose and test the next day?

 

[Fish Fan]

I have neophosphates should i dose and test the next day?

I've never used it myself, but I don't think that would be a bad place to start if you already have it on hand.

 

[billyocean]

Neophos is fine. May have to stay dosing it for a bit because your rock has probably leeched all thr p04 out so it may take a bit to grt the rock saturated. Just test and dose accordingly for a while.