SPS bleaching but Polyp extension full

[PhantomCavie]

Hey everyone, so I've been trying to figure out the issue my tank has been having as late. Here are the specs:

Salinity: 1.025 (calibrated refractometer)
Temp: 79.5 F
Calc: 460 (red sea)
Alk: 7.4 (low I know, working on bringing it up slow)
Potassium: 0.2-0.8 (red sea)
Mag: 1360 (red sea)
Nitrate: 0 (reading)
Ammonia: 0
Tank size: 40 gal breeder, 20 gal sump
Lights: 24" reef breeder photon LED
Corals: Mixed (LPS, SPS, Zoas, softies)
Ph: 8.2-8.4 (monitored by GHL profilux 4)
Dosing: B-Ionic 2 part 25ml a day, 15 min apart, alk first, then calc.
ATO: with RO water, TDS=1 read with separate hand held TDS
Feeding: ~teaspoon/day formula 2 small pellets (the green container)
Clean up crew: 2 or so quarter sized turbos, 5-6 Nasarius

Tank has been running for 4.5 years.
Bioload: 1 sm. occellaris, 1 sm. pygmy dwarf angel, 1 Midas blenny, 1 sm. leopard wrasse (less than 3.5 in), 1 striped high fin goby.

Filtration: HOB reef octopus 90, In sump reef octopus 202, both pulling dark brown skimmate. Phosphate pads (changed every 2 weeks ish). Phosban reactor outfitted to hold a small amount of purigen instead. Refugium with chaeto and a small LED set to only red and blue channels.

Here is the issue, I have nuisance algae in the tank, specifically bubble algae, calothrix, and some snotty looking stuff, not dinos though. Some of my SPS are bleaching or have STN, but still have full polyp extension, some of my LPS are fully extendend, others are rectracted, there seems to be no correlation between what is doing well and what isn't. Some SPS is flourishing, others that have been bright and colorful colonies for months have completely bleached, but still have tissue and colorful polyps. This is after at least a year of stable conditions and happy coral growth. I've currently sent away for a triton labs test to see if there is something in my water I can't detect. Other than that I'm at a loss for what could be up :headwallblue:

Any Ideas?

 

[PhantomCavie]

The part that perplexes me is also that I have phosphate issues, with no nitrate issues. Similarly my alk dip has happened with adding the same amount of 2 part every day, so alk is dipping but not calc. ALSO i don't dose mag at all, and I use reef crystals salt mix, but it hasn't dropped below 1350, even with only doing 25% water changes once every 3 weeks.

 

[RobZilla04]

Suggestions I can think of would be reduce the light intensity just a bit for a month and get those phosphates reduced. Steer clear of making any major adjustments. You can try GFO in a reactor and change the media every week or two. There are cheap effective reactors on Amazon. I used one until my algae and phosphates were gone, then removed it.

 

[ca1ore]

Your WQ seems fine. Perhaps the only red flag is that your ATO water is just RO, not RODI. Even at a TDS of 1, stuff can build up over the long term. What is your water change schedule? You could also try running a polyfilter for a while. It's the Popeil's Pocket Fisherman of the reef tank.

 

[mcgyvr]

I read...phosphate issues and alkalinity instability..
That right there is more than sufficient to cause all your issues..

 

[Horace]

Yeah, I tend to agree with mcgyvr. Stability is not shown by one time readings.

Btw your Alk is not low....that is where I would target.

Sent from my Nexus 6 using Tapatalk

 

[PhantomCavie]

I read...phosphate issues and alkalinity instability..
That right there is more than sufficient to cause all your issues..

I agree, but I guess my biggest concern is what could be causing my phosphate issues? I feed light and dose daily, test weekly, and do a 25% water change every 3 weeks. Also, with the chaeto in the sump, as well as phosphate pads don't you think it odd that my phos would be so high? Similarly, I have no explanation for how I have coral growth, but no dip in mag. Is that normal?

 

[pscheel]

My bet on the high phosphate would be the pellet food.

 

[mcgyvr]

Has your phosphate always been elevated?
What is it? what was it? How long has it been a problem,etc...?
I don't see any of that in your post above.. (I could be blind)
One time parameters are good but long term information is needed here..

Rocks "can" store phosphate and it can leach back out..
Whats a phosphate pad? brand?

Have you tried to run GFO in that reactor?
That should suck it right down and if it comes up again its likely leaching from your rocks..

1 teaspoon daily for your fish load IMO isn't really feeding lightly IMO..