Slow bleaching of some SPS

[A Reef Scene]

Some of my sps are bleaching out over a time span of 3 months. Is there anything I should look for?
Mag 1250
Cal 340 This is low
Phos .08
PH 8.1 to 8.2
And no detection of nitrate, nitrite and ammonia.
The sump is not on a auto top off, so the level will shift about 5 gallons in two days. Could the constant shifting of salt levels have this affect?
The tank is about 400 gallons.
The tank could use a lot more flow. And the lights are 400 watt 15000k
Temp is around 80 to 81 most of the time.
Main pump is a Hammerhead. I was thinking about replacing the impellerand seals to pervent the nut from rusting.( was wet on the last cleaning)
Any input would be great, thanks for the help.

 

[jroovers]

Your Ca is low. More than that though. What is your alk level? Probably one of the most important measures you want to know. Also your phosphates are high - depending on what kit you are using, you may actually be really high - alot of people have some phosphates in their tank but can't get a measure with a standard kit. I believe you want to be 0.03 or less. Are you running GFO? If you have shifting levels of anything, that won't help either. To me it would seem to be a combination of these factors.

 

[A Reef Scene]

I just started to run phosphate remover, the brightwell cubes. I'm also ordering in some GFO. The test kit that i'm testing phosphates with is the red sea pro. As far as the the alk level, that is the one test I did not do. I will test and post back. Could cheep light bulbs be a factor, as far as not the right amount of UV coating?

 

[Sawen]

I just started to run phosphate remover, the brightwell cubes. I'm also ordering in some GFO. The test kit that i'm testing phosphates with is the red sea pro. As far as the the alk level, that is the one test I did not do. I will test and post back. Could cheep light bulbs be a factor, as far as not the right amount of UV coating?

The Red Sea Pro phosphate test kit has the terrible tendancy to always read 0.08. It happened to me and many others. There are already many threads on this if you use the search button.

 

[A Reef Scene]

What would be a better phosphate test kit?

 

[DNA]

5 gallons our of 400 is around 1% swing in salinity.
That not much, but it's so easy to automate and keep constant.

Calcium levels are really low and you should not let it get this low.
Get a second test kit because they are not to be fully trusted.

Low flow is not what reefers recommend for SPS.

SPS are needy corals and you have mentioned a few things that could be improved to meet their needs so go ahead and upgrade your tank a bit.

Phosphates and algae hold hand in hand so if there is no algae growing in your tank it's hardly a problem.

 

[A Reef Scene]

Fedex just droped off two 3200 gph pumps like Koralias. That should help a lot. If these work well I will pick up two more.

 

[jroovers]

Before you do anything get yourself an Alk test kit. If you know someone in your area who has one of the Hanna phosphate checkers, borrow it, they are the most accurate. Then get your system as stable as possible - stable Ca, Alk, put your sump or refug on a reverse lighting cycle to minimize PH swings overnight. Get your salinity stable. Use dosers if you can to dial in your Ca and Alk. Stability in term of water parameters is the name of the game. Do some research as well on ULNS systems - if you are going to devote your tank to SPS, you may want to incorporate biopellets or carbon does - but that should come last after you take the other steps first.

 

[trentdingo]

Copper slowly increasing?

 

[ecvernon]

are your corals bleaching but still living with tissue in tact? or are they bleaching and die exposing skeleton? alk is very important check there and make sure its not some type of alkalinity swing related problem

 

[A Reef Scene]

The alk is around 9.5. The coral looks like its just getting lighter in color.