Sps stn

[bshow24]

A friend of mine (and yes, it's actually a friend haha!) has been dealing with SPS corals STN-ing for sometime now. They do well for 2 weeks then all of a sudden begin to STN. Usually he'll bring the corals to me and I'll hold em for a bit to see if they recover, and many have begun to do so (99% of these have been frags).

I've been in the hobby for a while but am nowhere near an SPS expert, so I was wondering what could possibly be causing this STN? We assume it's not any type of bug as we did dip and inspect before it went into my tank, found nothing. All parameters are consistent so no way it's a swing of any kind (Alk 8.5, Calc 440, Mag, 1400).

My thought was lack of light, as he was only achieving about 220 PAR at the surface, and about 150 where his SPS sit. The flow is relatively strong and doesn't seem to be an issue. I'm really stumped by this, any help would be awesome, I already have too many frags in my tank and want him to keep his own!

Other Params:
PH:8.2 - 8.4
Temp: 78
Nitrate: 5
Phosphate: .01

 

[Pife]

Salinity?

 

[bshow24]

1.024-1.025. I knew I forgot something!

 

[bshow24]

It might also help to mention when his drags STN, they STN from the bottom up.

 

[Reel North]

Strong flow can be just as bad as low flow. I've found that RANDOM indirect flow works best for me.

Salinity is a hair low. What's calcium, alk and mag.

And par is really low.

 

[bshow24]

Thanks for the response. I feel that's the main difference between my tank and his, as well as my lighting being stronger.

Calc, Alk, and mag all normal (440, 8.5, 1400). I told him to ramp up light intensity so we will see what happens there. Flow and low light are two big reasons for bottom up STN correct?

 

[Reel North]

Yes.

And parasites.

 

[bshow24]

If there were parasites, wouldn't they have been on there when we dipped? What kind of parasites would we be looking for? AEFW? Flatworms?

 

[tamama]

Sometimes the coral could be unhealthy to begin with.

Sent from my SM-G935F using Tapatalk

 

[Reel North]

I used to have no pe at all. Then I was over run with aefw, and lost a lot of sps. I had lots of rtn going on.

It could really be anything, but I noticed a world of difference, and now am clear of aefw, after using melafix marine at 4 caps per gallon.

In reality, it think it's likely low flow and low light. The trick is to eliminate possibilities until you find the answer

 

[bshow24]

I'm thinking low flow and low light because there is still polyp extension and growth from the corals, the problem is they continually STN. There's no way it would be from shading either because they are just frags.

His flow and lights have been adjusted, hopefully things will start to improve and he can take all his darn frags back!

 

[scar79]

Make sure your refractometer is calibrated properly. I had a mysterious bottom-up STN issue for weeks before I discovered my salinity was actually 1.027-8. In your case I would definitely focus on lighting first, but checking calibration is quick thing to rule out.

 

[bshow24]

I personally use TLF AccuraSea and am pretty sure he uses a solution to calibrate, but never hurts to double check.