STN with new SPS frags

[FarmerTy]

Hi All,

Want to pick the ARC collective brain.

My current SPS population is growing like mad, I can literally see growth on a dialy basis. Coloration is great after the dinoflaggelate recovery so all my colors are finally coming back to me. I have a population of approximately 50 different SPS species, ranging from easy to keep to quite finicky.

The thing that confuses me is the addition of new SPS corals. The hardier types come into my system and they are okay from day 1. The more sensitive corals I have noticed come into my tank just fine, but then start to STN very slowly at the base, which progressively gets faster until 3-4 weeks later, I'm staring at a white skeleton. The three types I've noticed this on are specifically blue hoeki, reef raft millie, and AquaSD strawberry shortcake. These are all more sensitive corals so it is understandable that they may STN, but just curious if anybody has had the same experience.

I actually have a Vivid Aquarium strawberry shortcake in my system that is doing great and growing like mad in my system, but the new one that is introduced begins to STN the next day after introduction.

I would blame flatworms but its only on new frags, older frags would show the same symptoms if they were present. I would blame my alk but it's pretty stable.

Only thing I can think of is my introduction process. I dip in Bayer Insecticide dip (worked perfectly fine with the introduction of all my other SPS frags), then I move it into the tank and leave it on the sand, then I move it slowly up the rock until I get it where I want it. The process doesn't allow for drip acclimation for the SPS frags, so once they leave the water they came from, they are introduced to the insecticide dip, then tossed into the tank with the new water quality parameters. Perhaps the shock causes the STN. Thoughts?

My params are stable:

Ca- 450ppm

Alk- 8.0-8.4 dKH

PO4- 0.015 ppm (Hanna)

Mg- 1400 ppm

pH - 7.9-8.1 (Ca Reactor keeps it lower than average)

Salinity - 1.026

Temp - 81-83 (keep it higher purposefully)

Lighting Schedule:

6hrs halides (3 x 250 watt)

7hrs T-5 (ATI blue specials, coral plus, and purple plus)

12hrs of blue LED stunners (aestetics only)

Equipment/Maintenance:

ASM G-3 skimmer - run 24hrs, empty 1/week

GFO reactor - replace media monthly

biopellet reactor - run 1/2 the recommended amount

carbon bag - passively run in sump

Feed fish once daily

-Ty

[Juiceman]

I dip my SPS with Coral Rx while I'm acclimating them to my water. I take out half of the water they came in, add the Coral Rx, then dump the amount of water I took out back in with tank water. and let sit for 15 mins. I don't drip. I would think they would definitly stress without water acclimation.

And as I've experienced before, sometimes the STN/RTN happens days or weeks after the initial stress event happens.

[jestep]

You can drip in a container for 1 - 2 hours, and then do a separate dip in tank water before adding them to the system. If everything else is doing well, I would suspect acclimatization as well.

Also, not sure if it's possible for ordered coral, but try to match the flow and lighting as close as possible, otherwise, put them in much lower lighting and work them up to where you want them at. I've noticed several times with multiple frags from the same source that 1 will thrive and the other doesn't make it and I would attribute it to the coral not being able to adapt to a different condition that what it was in.

[victoly]

personally, I've always had *worse* mortality rates when I try to drip acclimate SPS. I spit the shipping water 50/50, dip with half, return to the clean 50%, temperature acclimate and rinse with clean water before dropping them in.

[Timfish]

One of my suspicions would be the lighting is not as intense in your tank as what they were grown under. Is it possible for you to get the lighting the frags grw under?

[FarmerTy]

I figured my frag introduction process was a little abrupt for most corals, kind of akin to unplugging someone from the matrix. But with a very low mortality rate, it hasn't gotten me to change my ways. I will see if a more gentle acclimation process would work next time I try a frag.

Timfish, how come you suspect the lighting? I always thought I had decent lighting in my system with a 250-watt halide and 4 additional T5 bulbs (no pure actinic bulbs) over each 2' section of my tank. The lights are only 8-10 inches off the surface of the water and the tank itself is only 16-18" deep. Curiosity makes me want to test it with a par meter but I just always assumed it was a lot by normal standards.

[Juiceman]

One of my suspicions would be the lighting is not as intense in your tank as what they were grown under. Is it possible for you to get the lighting the frags grw under?

That's interesting. I had an echinata that was under a 400w halide that I acclimated and put in a low light area just to make sure I didn't cook it with my LED's and it RTN'd anyway. Could that have been why, a sudden decrease in par?

[jestep]

I seem to have worse problems when I immediately put new coral into high flow, high lighting. I can usually catch it if they start to bleach, but don't have near as many problems by reduced lighting at first.

[Timfish]

Timfish, how come you suspect the lighting?

I've seen die off similar to what you described that I was pretty sure associated with lower light levels than what the coral was under previously. I'm not saying I think lighting IS the problem here just it would be something I would check out if I could if it was my tank.

[FarmerTy]

Ah, gotcha Tim. Just passing along what you observed. I appreciate the insight.