I'm confused

[reef_zombie]

So after successfully keeping SPS for almost two years, I lost over 90% of my SPS this past summer after a perfect storm of conditions including over temp, pump failures and over doses.
I won't bore you with the details but after a few months 90% of my SPS were gone, while my tank slowly recovered and my LPS and softies continued to thrive.
I waited for months before trying to add a new SPS frag which soon stn/rtn. All the while I am checking my parameters which are perfect.
Fast forward months later to the present, almost seven months after the initial problem and I still cannot keep SPS without them rtn/stn within weeks.
My tank is a 90 with T5s, parameters as follows.
Alk 9-10
Mg 1350
Ca 460
P04 .03-.09
No3 3-5
Salinity 1.026


What am I missing

[MHG]

What kind of sps? Try something easy like purple stylo....

[reef_zombie]

One other impression I get is that my tank seems "dirty".
While my SPS are doing lousy my LPS, softies and fish are thriving, many doubling in size over the past seven months.
Obviously my bio load is increasing , maybe my protein skimmer is maxed, it's an SWC 160

[captjab]

Did you have a heater bust in the original crash? Just taking wild guesses to try and help.

[reef_zombie]

Thanks but did not have any heater breakage

[rsaha]

Do you run carbon? With lots of LPS and particularly softies perhaps there's something in the water column making your tank not so SPS friendly? How's your flow? 30x turnover plus?

[Chaotic Reefer4u]

Is it good to run carbon with sps rsaha?

[rsaha]

Is it good to run carbon with sps rsaha?

I don't know the answer to that question. Some people do, some people don't. I don't personally but my tank is SPS dominated with very few LPS. The OP sounds like the tank has alot more LPS/softies which is why I was asking. One use of carbon is to control the effects of chemical warfare that goes on in mixed reefs.

[reef_zombie]

I do run a reactor with carbon and always have. I have plenty of flow from an Iwaki 55rlt and two Jebao WP25s.

My tank was primarily SPS dominant, my other corals currently include a very large hammer (30 + heads), goniopora, large toadstool, clover polyps, ricordea, plate coral, a large rock of zoas and large gorginian.

[Chaotic Reefer4u]

I don't know the answer to that question. Some people do, some people don't. I don't personally but my tank is SPS dominated with very few LPS. The OP sounds like the tank has alot more LPS/softies which is why I was asking. One use of carbon is to control the effects of chemical warfare that goes on in mixed reefs.

Thank you rsaha, question answered:-)

[rsaha]

Stray voltage? Something rusting around your sump? Maybe a few months of 20% weekly water changes to be sure it's not something in the water?