What's killing stony corals in my tank ?

[Katze]

Hello everyone !

I have more than a year old reef tank. I started to keep corals in this year february. First I started with zoas they grew ver well so I bought an euphyllia paraancora which died in under 2-3 months of struggle, then I tried a dull colored acan, survived but ~60% of the coral had died with only 2 heads remaining and no tissue connection. I also had a caulastrea half a year ago, I've been given multiple sps corals for free to try all died (except that acan) but never the softies nor my gorgonian.

Parameters:

PO4: 0,26 (measured last time on Hanna ULR) -> using RoDi water TDS: 0
NO3: ~100 (I have no literal idea what to do so far I tried: ceramic filter media, cleaning mechanical filtration more often, nopox, refugium but nothing works)
-> my fish get half a cube of mysis
-doing 10% WC/week
Salinity: 1024-1025
-running activated carbon

Light settings:
Maxspect Ethereal
White about 60-80%
Blue: 90%
The rest are either 10% or 15%
it's on from 7:30 until 20:00 however it's always on full intensity since I don't have a controller

Livestock:
Scopas Tang (I never seen them nipping at any coral)
Purple Fire Goby
Lyretail Anthias
Mandarin Dragonet
Clownfish
Damselfish

CUC: Thousands of copepods, large amounts of snails and limpets + bristtle worms (the good kind)

Corals: bunch of kenyatree, zoas (all growing well), 2 acan lords (one is suffering other is interestingly okay),1 gorgonian, 2 discosomas and 1 ricordea
-I always had problems with stony corals and I don't know why,

So I need help figuring out what kills stony corals in my aquarium!

 

[The Opinionated Reefer]

You do not mention how you are maintaining alkalinity, or what you alk and calcium levels are at. It will be your alk and calcium levels. These need to be tested several times a week and maintained via dosing.

In all honesty, if you do not know this stuff then you don't even understand the basics of reef keeping.

 

[Dburr1014]

Hello everyone !

I have more than a year old reef tank. I started to keep corals in this year february. First I started with zoas they grew ver well so I bought an euphyllia paraancora which died in under 2-3 months of struggle, then I tried a dull colored acan, survived but ~60% of the coral had died with only 2 heads remaining and no tissue connection. I also had a caulastrea half a year ago, I've been given multiple sps corals for free to try all died (except that acan) but never the softies nor my gorgonian.

Parameters:

PO4: 0,26 (measured last time on Hanna ULR) -> using RoDi water TDS: 0
NO3: ~100 (I have no literal idea what to do so far I tried: ceramic filter media, cleaning mechanical filtration more often, nopox, refugium but nothing works)
-> my fish get half a cube of mysis
-doing 10% WC/week
Salinity: 1024-1025
-running activated carbon

Light settings:
Maxspect Ethereal
White about 60-80%
Blue: 90%
The rest are either 10% or 15%
it's on from 7:30 until 20:00 however it's always on full intensity since I don't have a controller

Livestock:
Scopas Tang (I never seen them nipping at any coral)
Purple Fire Goby
Lyretail Anthias
Mandarin Dragonet
Clownfish
Damselfish

CUC: Thousands of copepods, large amounts of snails and limpets + bristtle worms (the good kind)

Corals: bunch of kenyatree, zoas (all growing well), 2 acan lords (one is suffering other is interestingly okay),1 gorgonian, 2 discosomas and 1 ricordea
-I always had problems with stony corals and I don't know why,

So I need help figuring out what kills stony corals in my aquarium!

Was the tank started on dry rock?

Water changes can bring down the no3. Po4 is bound to the rock/sand and will need gfo or the like to get that down.
Is like to here about your flow also.
And the alk, calcium/mag.

 

[Katze]

In terms of alk, Ca, and Mg: I have the 2 acans (they are struggling) nothing else only the softies !!! Whenever I tested (usually monthly) everything was in line with 10% weekly waterchanges ! Which means: Mg ~1350, Ca under 460 KH 8,6 and salinity either 1,024 or 1,025.
YES the tank was cycled with dry rock but about 30-40% was live rock, either from my lfs' tank or straight from the sea.
Well I had very bad po4 but since I use Di it has been solved so that's fine.
But the nitrate isn't and I don't know what to do with that as mentioned, nothing helped so far.

 

[Katze]

+ Today it turned out that I had stray voltage in my tank, I solved it ! But then softies did not care about that.

 

[Dburr1014]

RODI will only help. Could also have been a problem.
Also, try and stay north of 1.024 if you can.
IME, I get some sad SPS down there.

 

[Katze]

Yeah, I have one zoa which always closes when it's under 1.025
But still the mistery behind lps and sps not surviving isn't solved.

 

[Katze]

Salinity is 1025, an acan lost quite a few tissue while zoas grow...