Sps paling/rtn

[Matthias7]

i have had my tank running for over 2 years now with almost no issues. In the last 3-4 months my sps has been in steady decline. I have lost of few large colonies. It seems as though the system maybe headed towards a crash. The parameters that I measure are all within a good range. Sg 1.025, alk 8 (consistent), ca 450. Total water volume is about 325 gallons. My phosphate measures 0 although I am at the tail end of cyano with a small amount of gha. Nitrates measure 0 by an API test. I bought a Red Sea nitrate test today (not the pro) and it tests higher, unsure of the accuracy due to the "leveled spoonful". At any rate my sps are becoming pale some are rtn'ng full colonies or frags can be gone in one night. Unsure what else to do here. I am now only dosing alk and calcium.

 

[Macdaddynick1]

Your nitrates are low and phosphates are high, test for phosphates .

 

[drawman]

Have you always ran your nitrates at 0 and are you carbon dosing? You may want to try to get some nutrients back in your system but don't swing too far the other way. How bad are your algae outbreaks? They may be absorbing your nutrients as well...

Have you checked for anything else (ie rusting magnets) or made any changes before the decline?

 

[Matthias7]

Unfornately I have made a few changes prior to decline the biggest was a pretty serious Alk spike (that was months ago however). I have also changed my lights I removed some old t5's and replaced with 2 250 watt halides. I have 3 kessils running with them.

Your nitrates are low and phosphates are high, test for phosphates .

Phosphates test at 0. Some algae in the system not overwhelming just small amounts.

 

[Macdaddynick1]

Unfornately I have made a few changes prior to decline the biggest was a pretty serious Alk spike (that was months ago however). I have also changed my lights I removed some old t5's and replaced with 2 250 watt halides. I have 3 kessils running with them.

Phosphates test at 0. Some algae in the system not overwhelming just small amounts.

oh ok then drawman is probably right , the problem could be that your nutrients are too low. If I remember correctly , there is a balance between the light intensity and the nutrient level. Im not sure exactly how it works but basically you can't have too much par and have your nitrates and phosphates being 0 . Just thinking this through , I think your acros are starving and you went from old t5 bulbs that most likely lost a lot of par , to 2 250 mh . I'm not sure how powerful those things are but i think those give off quite a bit of par especially when they are new.

Here's what I would do , if you have an access to par meter that's awesome . check how much par your getting this could be important because acros don't always bleach when they get a light shock , they usually rtn.
Otherwise.
1) make sure your basic parameters are stable, ca, alk ~ 8 somewhere, this helps in low nutrient systems. and mag .
2) flow - make sure you have enough flow in the system.
3) No3 - ( my indicators of low nitrates in the system is 1) pointy tips on birds nest coral 2) burgundy cyano 3) I practically never have to clean the front of the glass. Get some medical grade potassium/or sodium nitrate, mix a few teaspoons in a 500 ml of water ( there are instructions somewhere on the sps section ) dose 5ml-10 ml per day , I would suggest you start very slowly . Test for nitrates and dose , try to get up to 5 ppm nitrates. When you start dosing nitrates you will see thin film of algae growing on it thats when you slow it down with dosing for a day or two, Then check nitrates again,
4) Po4 - get some mysis shrimp and start feeding your fish a little more, this will add both nitrates and phosphates. Don't dump too much food in all at once, because a fast spike in the phosphates will rtn acros faster than you can blink .
5) of course figure out your light may be raise them slightly.

Do everything slow and try to get to .02 on your po4 and to 5 on your no3. once you get there, step back and stop dosing or overfeeding , in the next few days see if your po4 and no3 gets consumed. then get them back to your required level.


So in summary , 1) ca- 420 + Alk 7-9 , (keep it stable) MG ~ 1350 . 2) Flow, I'm sure thats nor your problem. 3) No3 - get it to 5 and keep it there, 4) Po4 get it to .02 and keep it there 5) either remove kessils for now or raise the lights higher 6) your corals won't come back the next day and you might still be losing corals a good month from now, but if you keep at it most should start recovering .

 

[Matthias7]

Awesome thx mac. I have read that people are using spectracide stump remover it's readily available so I will try that. No access to a par meter unfortunately but I'm sure it is high. I may cut back the chaeto and see if that helps? The cyano that I have in the system is a dark burgundy color so I believe it certainly could and should be a low nitrate issue. I also skim 24/7 and do daily automated water changes of 1 gallon per day.