Help Prevent Involuntary SPS Slaughter

[MrNYCeGuy]

Welcome to my tank regression thread!

Over the past few weeks, I have watched in horror as my tank has begun to slowly descend into chaos. My tank was once a happy place with a few SPS frags growing slowly and steadily over time. Things started to degrade three weeks after I added a small 1 gallon hang on the back refugium to my tank. I filled it with both Cheto and Caulerpa and watched both flourish in my refugium, almost doubling in size over a two week period. During the initial three weeks, my skimmer cup was almost never filled I thought this refugium thing really works wonders. Happy times!

All was great until two weeks ago I began to see some polyps retreating from a few corals and STN set in a few days later. This seemed like a logical time to test my nutrient levels…sure enough, 50 ppm nitrates!!! Quickly I started looking for the suspect and it seems as though the Caulerpa and Cheto had been killing each other off as I found brown dead particles of each at the top of the refugium. Also compounding the issue was the fact that my skimmer had not been running properly this whole time.

Measures had to be taken so I removed the Caulerpa as I have read (and it might not be true) that it can release some toxins when it’s in a small competing environment, but left the Cheto. Also, I fixed my Benedict Arnold version skimmer (I have my eye on it now) to its proper working order, added activated carbon (I ran no carbon previously), and did 2 X 50% water changes over the course of two days. I also did an ICP test after the water changes and it only came back elevated for Molybdenum (didn’t realize geology was a prerequisite for this hobby). Checked my magnates in the tank for signs of corrosion and didn’t really find any.

It has been a week since the water changes, skimmer fix, and activated carbon addition and half of my SPS corals are still STNing or showing little signs of PE, while half have started to recover. My question here is have I taken the necessary steps to avoid a full system crash and I should just leave everything alone for now or could there be something else causing the further STN? #reefsquad



Equipment



29 bio cube

UFO Grow Light 150 W on refugium

1 gallon hang on the back refugium

18” SBReef Lights LED, turned down to 3% whites and 8% blues…super powerful light…yea have killed some stuff with it in the past…my bad

2 X 425 gph Koralia pumps

1 X Jebao wavemaker

Aquamaxx WS1 Skimmer- rated for 65 gallons…and is a turncoat at times



Water Parameters

Nitrates: 5 ppm

Water Condition: Very clear

ICP Test Results:

 

[29bonsaireef]

I would back off the carbon. In a tank that small you don't really need it.. wc will fix just about any issue you have with params.

I'm not familiar with your lights but 3 and 8% seems extremely low to me? Also, I'm not sure if you really need the oversized skimmer AND the fuge for a nano, but that's just my opinion.

If things are recovering I would just keep doing what you're doing for now. If you need to make changes go one at a time. Just curious how old is the tank?

 

[MrNYCeGuy]

Thanks for the reply! So I've cooked a couple of my corals due to overexposure to the lights. It’s funny my par, based on lux meter readings and conversion into PAR is like 100 PAR, however, if I turn up the power on my lights I bleach my acros. I need to read more about PAR and PUR.

The tank has been up and running for 5 months.

 

[29bonsaireef]

Yeah I would really look into the lighting. 100 par is not very much light at all. Maybe someone that's familiar with those lights will chime in.

With tanks that size you can really throw off the balance when you start changing things or adding stuff. I would just keep doing 5-10 gallon weekly or bi-weekly WC until everything is in a recovery stage.

 

[MrNYCeGuy]

I would absolutely agree with you that the par is very low, seemingly way too low but if I raise the lights at all I see bleaching occur. It might be an issue with my lux meter or calculation and conversion into PAR. My lights are about 15 inches from the top of my tank.

For sure plan on keeping up with small water changes in the future.