LPS corals receding
 

so ive noticed that a couple of my scolies have started to recede (some more than others) and pretty much all my euphyllia are now dead. i have increased gyre output from 40% to about 50-60% to combat algea, which i assume is why my euphyllia are now done, but i dont get why the scolies are dying.

Here are my paramters. I have noticed that they have risen since i switched from AF reef salt to Salinity.

Salinity: 37ppt
Cal: 440 - salifert
KH: 8.8 - salifert
nitrate:0 - api
phos: 0.04 - hanna
water changes: every 4 weeks, about 60 gallons (25%) using Canadian Springs bottles

based on web searches, all seem to be fine except my phos, but even when i had a phos reading of 0, i still had algea issues, so im not quite sure what im to do anymore.

i've been dosing phosdown every 2 days to combat the algea issue. zeobak 12 drops every wed & sat, and upped my skimmer to fill up every 2-3 days. I don't dose any alk or ca and my parameters stay steady. Feeding has been cut back to once per day.

Is there somthing i am missing or not doing that is causing this?

Po4 at 0.04 ppm is great. Po4 at 0.00 ppm is not good. If you had more it rate in your tank you'd probably be able to keep PO4 down without the PhosDown.

What do you have for clean up crew? What type of lights and what is the light schedule?

When you do a waterchange do you clean off the rocks with a baster and vacuum the sand or do you just take water ot and out water back in?

"If you had more it rate in your tank you'd probably be able to keep PO4 down without the PhosDown."
- more what?

"What do you have for clean up crew? What type of lights and what is the light schedule?"
- CUC: couple of trochus snails, there should be some nassarius in there, and 4-5 zebra hermits
- lights: 3 x kessil 360, running from 2pm to 9pm
- supplement with 2 x t5 (coral plus & blue plus) from 4pm-8pm

"When you do a waterchange do you clean off the rocks with a baster and vacuum the sand or do you just take water ot and out water back in?"
-vacuum gravel yes, basting rocks, not so much

Maybe something in the water, I would make the switch to ro/di if possible.

If you had more NO3 you're PO4 will come down.

Myka's advice was meant as "Po4 at 0.04 ppm is great. NO3 at 0.00 ppm is not good." She typo'd.

You're bacteria is NO3 limited right now. Get your NO3 up and PO4 will come down. Carbon dosing helps.

Also, blow off your rocks before you do a water change every time. :thumb:

Salinity is pretty high at 1.028 , I would buy a Salifert nitrate test to get a better idea where it's at for sure. If the nitrates are truly 0 then your LPS are not going to be happy , and as someone already mentioned will make your tank no3 limited and not allow bacteria to consume po4.

I also agree with investing in an rodi system. How often does the film algae regrow on the glass after cleaning ?

Look up redfields ratio, but based off your parameters i dont think that is your issue..

It would be unusual for for cal and alk to "stay steady" without dosing and and doing water changes every 4 weeks... but if your levels are acurrate and stay steady i would think it may be some contaminant..

Are you filling 12 canadian springs bottles to do water changes?

How do you get your water?

Sorry, more nitrate...auto correct typo. Get a better NO3 kit to conform your testing - I like Salifert or Red Sea Pro.

Lighting looks fine. Your CUC is sadly lacking. I'm betting if you added a bunch of CUC the algae would get eaten and not come back as long as the CUC is alive still.

You said 60 gallons is about 25% wc, so your tank is probably a 180 or 230 depending on sump?? If so, I'd suggest 10 Trochus (15 if they are small) and 20 Scarlet Hermits (not other types) to start. See where that gets you - you may need quite a bit more.

Basting is one of the best ways to help combat an algae problem.

I missed that 37 ppt...that's walking the edge of safety and if your calibration is off this could easily become 30 ppt which could cerainly kill your corals on its own. Natural seawater is typically 35 ppt and there is no reason to aim for any other number in a reef tank. Make sure you calibrate with a SEAWATER calibration solution (not sodium chloride solution, not ro water).

gotcha. I picked up a bottle of NO3PO4 so will start dosing that this week. thanks