Neptune Aquatics

STN on some corals and can't figure out why...

Eight

Eight

Guest
BARcard
I've been struggling with a few corals in my tank and wanted to see if anyone has any advice. I can't figure out what's wrong, quite frustrating.

Parameters
-----------
Salinity: 1.025
Temp: 76 to 79 (It temporarily spiked to 81.2 during the heat wave)
PH: 8.0 to 8.2
Alk: 8
CA: 400
NO3: Undetectable
PO4: Undetectable
Stray Voltage: None, tested with multimeter.
Running ozone through skimmer (Could this be it?)

Most of my corals are doing fantastic. I have an extremely long haired milli that has PE of about 5mm. GARF bonsai looks great with excellent PE, pink milli with blue tips colony looks good, smooth skinned green deepwater acro is growing, Dolphin bonsai is great, various monti colonies bright and growing, etc. All of my softies and my acans are fantastic.

Some corals, though, mostly SPS frags are really not looking good. The following have slowly been STNing over the course of the past month:

Tyree true undata (less and less PE and now almost dead)
ORA Red Planet (This used to be a stunner in my tank and now it's turning brown. It's actually growing still and has decent PE, but it's gone from metallic green and red to drab pale green, almost tan)
DBTC Palmer's blue milli slowly STNing
An old frag of green/red milli that used to be super hardy is slowly STNing as well
Oregon Tort frag, STNing on the underside.
Sunset monti (Doing ok, but not as well as the other montis)

I've noticed that the STN tends to start lower in the frag, usually on the side, but not directly at the bottom. The frag just gets paler and has less PE until it finally dies. It's a very slow process.

I am using a combination of D&D salt and Seachem. I have decided to up my water changes to see if that helps.

Anyone have any other ideas? (Should I just chalk this up to "Some corals just don't do well in good tanks and we don't know why?")
 
Ok, cut the ozone and will give that a shot.

Bulbs are 250w Reeflux 20ks in Lumenbright reflectors. Dimmable CoralVue eballasts, turned down 20% or so, so I don't think it's too bright...
 
The experts will need info on Mag too .. Sorry couldn't help you out man.. Did the problem start when you start dosing ozone?
 
Will test mag later tonight. I should keep a more detailed journal... I don't recall if it started with the ozone or not. I want to say that I was having problems before the ozone, but now that I think of it, it could be ozone...
 
Phong is correct, when I hear that montis are not happy I think of Mag, hopefully you have a decent kit (not Red Sea).

Also, I've never had issues when running ozone properly and I run it on several tanks, in fact I really like it.
 
You guys are good.

Just tested my Mg and it's at 1600 using an Elos test kit! That seems really high. I suspect it might be the DD salt. They advertise a higher Mg content than normal and perhaps my bucket is really too high. (I haven't supplemented any Mg either...) Grr.
 
Between the bad Reef Crystals batch and this super high MG salt from DD, I have lost more corals to bad salt than any other cause in my tanks! Thankfully I have a sack of IO left. I'll try a WC today.
 
I'm in the same boat Jason, I lost quite a few nice pieces during the RC meltdown and I tend to be pretty lax when it comes to testing and all that jive.
 
Mg at 1600 can be ok.

Alk looks a bit low to me.

If your kit isn't precise, or reads a bit high, that would be enough to cause problems.

Low alk will show recession starting at the lower parts of the coral.
 
Yeah, that whole RC fiasco was very frustrating. I didn't understand why things were dying so of course I just did more water changes with the salt. No wonder Drs. Foster and Smith was so generous with replacing the bad batch. Too bad they didn't replace the corals I lost too!

I checked the DD salt for Mg and it came out at 1450. I am not quite sure why the Mg in my tank was 1600 though. Anyways, I cranked up the Litermeter to change out the water faster and mixed IO in with the water that I had already made. I think the Mg is beginning to drop.

Mr. Ugly, is 8 really too low? I had heard that was a pretty good target. Lots of the ZeoVit guys sometimes target 7 or 8, so I hear. I added some sodium bicarbonate to bump the Alk up to 8.5. Will add some more tomorrow to bring it to 9.
 
8 dkh is 2.96 meq/l

That's kind of borderline and doesn't leave any room for alk to drop safely.

I tend to go for 3.8 - 4 meq/l, 10-11 dkh.

If you're using a count the drops type kit, you might be at 7 dkh (2.59 meq/l). Or even lower depending on your procedure.

That's low enough to show alk problems, and does fit your symptoms.

Worse case would be that you are slightly below 7 dkh due to kit and procedure issues, and you are maintaining alk with 2 part so that you are dropping signiificantly below even 7 between doses.
 
Yah, that RC thing sucked. Lost $$$$ in corals, and got all depressed.

I went on a pseudo break for about a year with my tanks barely running.

I'm only now just getting back active with my tanks.
 
I agree with Norm, I have a feeling its low alk. Maybe a bad alk test kit? Are you using salifert to test your alk?
 
i agree with Norm and Ian, i might be your Alk.

It happened to me in the past month. my alk dropped from normal 9-9.5 to 8 and lost my Candlelight Acro and Purple Monster colony.
 
Funny, I ran my tank at 8 dkh for almost two years using a count the drop test kit and never had problems until I raised my alk to 10-11 dkh, to each their own I guess. I'm now back down to 8-9 dkh.
 
tuberider said:
Funny, I ran my tank at 8 dkh for almost two years using a count the drop test kit and never had problems until I raised my alk to 10-11 dkh, to each their own I guess. I'm now back down to 8-9 dkh.
Click to expand...

What I am saying is something might be wrong with the test kit. Not that 8 is too low.
 
I bumped my Alk up to 9/10 and have brought my Mg down to 1400-1450.

It's too early to tell, but I *think* things are looking better. I was almost sure that I would lose the whole true undata frag, but it's definitely stopped STNing. The other corals that were doing fine, still look fine.

Unfortunately because I altered both parameters at the same time I won't be able to tell if the Mg or the Alk was to blame. :p
 
You must log in or register to reply here.
Back
Top