STN/RTN every time I purchase a colony from same LFS

[amcvay1979]

So I've spent a good bit of cash on 3 really nice Acro colonies from my LFS that I love and have a good relationship with. But I'm getting really tired of dropping a lot of cash on nice pieces only to see them vanish in a month or two, so here's what happened and what I've done. I'm only coming up with 2 conclusions;

1st piece I bought was a large (about 8 to 10 inch) colony of tabling acro, fleshy pink colored. It did great at first, it had PE when I fed the tank, but it I probably placed it too high with my AI 52's so it STN'd about 3 weeks after I got it. I dipped it, fragged it and still lost the entire colony. This was about 3 months ago, tank params were pretty close to what I run today; Nitrates about 5 to 8, Phos 0 to .10, Alk 8, Cal 500, Salinity 35 ppt, 81 degrees

Next purchase was a pale yellow acro that almost glowed neon yellow in actinic lights. I started it much lower in the tank over 2-3 weeks then moved it up. It did very well until lately it has started to lose large amounts of zoos and it's barely keeping the color now. This was about 1.5 months ago

About 3-4 weeks ago I purchased a nice green acro/bushy acro colony that had amazing PE as soon as I acclimated it. I started it off lower in the tank and it's still near the bottom. Then STN began on the bottom and moved over the middle/top. So I decided to reduce temp to 78 and this seems to have either slowed it down or stopped it completely. I dipped this colony when I saw STN but it continued to spread until I lowered temp to 78.

I asked my fish store guy what temp they keep their tanks at and they keep a very cool temp of around 75 degrees. I keep my Alk low because I carbon dose and now dose some zeovit additives, but don't run the rocks.

Now here's the weird wrinkle. I have 15 SPS frags that are over 3 months old and none of them have RTN/STN and have been acclimated the same way, dipped the same way and started off low in my tank and are now very high. So it seems only the acro colonies from my LFS experience STN/RTN. So here's what I'm thinking;

1. Temp has been too high at 81 vs 75 from the tanks they came from
2. Carbon dosing in my tank vs no carbon in LFS tank causes STN/RTN
3. I need to switch to a lower ALK salt mix so my water changes dont swing ALK too much. Typically I do 18 gallon changes ever other week on a 150 tank. I'd like to get my ALK under 7 but after WC's it can go to 8.5 to 8.7 until I let it fall back to 7.7 to 7.8

So anything else I'm missing?

Current parameters are;

Temp: 78
Salinity: 35ppt
ALK 8.2
CAL: 480-500 (don't dose this)
Nitrates: 2-4 ppm
Phos: 0 undetectable since dosing Zeovit

I dose Zeo: Sponge power, coral vitilizer, coral snow, aminos (haven't dosed this yet), K strong, Pohls Extra Special, Potasium/Flouride/Iodine.

I really only dose Sponge Power daily, the rest are every other day, once a week. I feed the coral vitilizer 2 times per week.

I've got outstanding PE on all my colonies and frags with exception of the pale yellow acro. I dose Vodka/Vinegar over 7 hours during daylight hours via a dosing pump, currently 32 ml's per day. I still get some brown algae on the glass but lately it's been more white film on the glass daily.

Anything I'm missing to help solve my RTN/STN Issues besides not purchasing colonies from my LFS any more?

 

[C.Eymann]

you are purchasing wild/maricultured colonies? everything you are doing sounds correct, however, what about flow? frags, esp aquaculturedo ones are pretty forgiving on flow. However colonies from the wild that are used to broad ocean surge (esp tabling ) pretty much seem to always slowly decline when they don't receive similar flow patterns.
just something to consider.

 

[Mark9]

Why are you aiming for alk under 7?
Shoot for 8.4 and keep it constant.
Many corals hate alk swings.
And I think you are dosing way too many other things, vinegar, trace elements, etc.
Work on getting your nitrates down.

 

[C.Eymann]

Why are you aiming for alk under 7?
Shoot for 8.4 and keep it constant.
Many corals hate alk swings.
And I think you are dosing way too many other things, vinegar, trace elements, etc.
Work on getting your nitrates down.

those nitrates don't look too hight to me. Also really can't say that's too much vinegar / dosing without knowing system volume

 

[Reef Frog]

The automatic answer you'll usually receive on the cause of STN/RTN topic is usually "alkalinity swings". That just seems too simple and you have to wonder if there are more pieces to the puzzle waiting to be discovered.

I've seen suggestions that a bacterial infection is at work, but haven't run across any credible research on the topic. It certainly seems plausible. We already know that tissue necrosis in humans is almost always a bacterial event. Why not in a coral? We already know temperature has a profound affect on the life cycle of bacteria. We already know it is an opportunistic organism....

Perhaps a combination of alk swings, higher temperatures and the availability of nutrients and/or disolved organics together can trigger these events by making an ideal environment for rapid bacterial reproduction. Or maybe one retailer's stock tank has this theoretical bacteria present & another one does not.

Of course, all of the above is pure speculation but I think it deserves consideration. A precautionary treatment with aquarium antibiotics during a QT period may be worth considering. No answers here, just questions & guesses.

 

[Mark9]

those nitrates don't look too hight to me. Also really can't say that's too much vinegar / dosing without knowing system volume

There's alot going on it that tank with all the additives, doesn't look stable.
The alk swing is an obvious sign of concern.
And if he's dosing vinegar and still has nitrates, then there is an underlying problem.
Corals like stability.
If I was the OP, i'd go back to basics, get ca/kh/mg right, solve the nitrate problem, then slowly add variables back to see what rocks the boat.

 

[C.Eymann]

There's alot going on it that tank with all the additives, doesn't look stable.
The alk swing is an obvious sign of concern.
And if he's dosing vinegar and still has nitrates, then there is an underlying problem.
Corals like stability.
If I was the OP, i'd go back to basics, get ca/kh/mg right, solve the nitrate problem, then slowly add variables back to see what rocks the boat.

Minus using the full zeovit system it looks similar to a zeovit dosing regime.

Also, yes it is possible that the Alk swings are ticking off the new colonies, however NSW level is 7 and many ULN systems run lower alk levels as it is theorized that having a ULN system makes corals more susceptible to alk burn.
Also 2-4ppm of nitrate is actually considered by some to be ideal by some sps keepers.

His waterchanges causing a swing is a concern but i can't see it being a reason for every new colony to be RTN/STN when the other corals are fine.
I agree with Reef Frog, I think there is something else going on here rather than your standard (alk isn't stable enough).

 

[amcvay1979]

Thanks for the suggestions. I'll attempt to clarify my ALK. Since I'm attempting to run ULNS I'm shooting for 7 dkh and I do get it there and keep it there until my next water change with IO or Reef Crystals. I'm going to change to regular Red Sea and see if that solves the swings. I dose ALK via dosing pump to keep it at my desired range but lately I just keep it off until I get it at 7.

 

[amcvay1979]

And my tank volume is 150 less rocks and sand, my sump is about 18 gallons total.

I'm assuming all of my acro colonies are wild but that's a total assumption and assume my frags are wild caught as well, but both could be captive grown as well.

 

[amcvay1979]

Also, input water TDS has crept up to 39 ppm so it's time for a DI resin swap. I'll do that tonight but I doubt that would be the main RTN/STN culprit?

 

[Docdiggy]

39 ppm could be a problem if your constantly using it for top off and wc.

 

[flyhigh123]

try a colony from a known good shop... see if you still have RTN...

 

[amcvay1979]

It would have to be online as my town only has 1 real source for SPS. I got all 15 of my sps frags on eBay and they're doing great.

 

[amcvay1979]

For flow I have a 4 foot tank and I run 1 gyre 150 and 1 gyre 130, opposed from each other both on full blast and they're on a pulse mode that sometimes overlaps, sometimes doesn't. Pretty strong flow from these 2.

 

[amcvay1979]

Quick update: since I've lowered my temp to 78, increased my carbon dose, my RTN/STN on my main piece of acro that was slowly bleaching has stopped. My Nitrate is undetectable with Red Sea Pro, Phos undetectable by Hanna Checker and polyp extension on every SPS is insanely good. My Alk is holding steady at 7.7 too. I think my issue was high temp and possibly difference in Alk from my LFS to my display tank.

I'm going to purchase 1 more SPS colony from them later this week and see if I get any RTN/STN in 30 days and then I'll know for sure.

Thanks for the advice all.

 

[dkeller_nc]

Also, input water TDS has crept up to 39 ppm so it's time for a DI resin swap. I'll do that tonight but I doubt that would be the main RTN/STN culprit?

Something about the way you worded that is confusing. Do you mean that the water going into your RODI system is 39 ppm, or do you mean the output (product) water from your RODI system is 39 ppm? If it's the latter, that's a big deal. 39 ppm output water suggests a total exhaustion of your DI, and a total exhaustion quite a while ago. Depending on what's in your municipal water (or well), exhaustion of your DI could well be allowing a good deal of dissolved metals that you don't want into your tank, including copper.

If you're on municipal water and you're changing your carbon blocks out on the same schedule as your DI resin, there's also a definite possibility that you're allowing chloramine through the system as well.

 

[amcvay1979]

It was the latter, my water after the RO Membrane is around 30, after the DI was 39, so I put a new DI Cartridge in and it's back down to zero. I run a whole house Whirlpool filter that self regenerates every 8 days, this effectively removes heavy metals and chlorine from my input water, from there the water goes to a whole house softener, then to the RO/DI system. So typically I change out the carbon blocks (I run 2 of them after my sediment filter) after 2 DI refills.

Obviously my DI exhausted faster than usual which I would blame on a seasonal source water turnover, our muni water is supplied by a lake and every fall the water turns over and becomes full of organics. I'm assuming that's what happened, also we're a farming state so the runoff after harvest is full of nitrogen as well.

I'm going to setup multiple TDS meters to better monitor my water Pre RO, post RO and post DI to keep better tabs on my system for better filter changing regimen.

 

[DDon]

30 out of the RO is pretty high which will exhaust your DI fairly quickly. You may be due for a RO membrane change. Any idea what the inlet to the RO is?

 

[d2mini]

FWIW, I won't buy wild/maricultured colonies.
They are much higher risk, change color, etc.
Would much rather by a frag of something grown in captivity where it's used to growing in a box of water and I know what I'm getting (and not getting, i.e. pests).

 

[organism]

Flow is everything for new colonies, especially bigger ones. Light really doesn't matter if they're not getting good flow since that can make them peel really quickly. For my SPS they get Bayer dipped then low light with good flow until they're happy and settled in with all the polyps out, after that slowly move them to the desired location.

Giving a new colony a ton of light by putting it near the top of the tank along with low flow is pretty much a death sentence. You're used to frags which are much more forgiving... Colonies wild or maricultured are a completely different thing. Every inch of that colony inside and out needs to be getting good water movement.