Is this RTN on my green monti cap?

[JAG107]

I noticed these white areas yesterday and seem to have gotten very slightly larger overnight, started from the outer edge working in. Do you think this is RTN? Tank params haven't changed at all this week, everything's pretty much same temp, nitrate 25ppm, phos 0.10, salinity 1.025. I've been working on lowering the nutrients but they just won't come down, do 20% water changes weekly. Ever since the eel kicked the bucket the levels are through the roof (relatively), but I don't know why nitrate or phosphate would cause tissue loss, maybe just slow the growth down. None of the other SPS seem affected at all.

 

[dustin_P74]

its either bleaching or its montipora eating nudibranches, which will eat all the tissue on the monti, you should take it out and give it an iodine dip asap. and from now on i would give all your corals an iodine dip

 

[ccCapt]

How fast is it receeding? RTN=rapid tissue necrosis, STN=slow tissue necrosis.
Does that clown goby stay in the coral alot? It may be irritating it. Is that an urchin there too?
25 nitrate is high for corals. You need to really work on getting that down.

 

[JAG107]

The clown goby hangs out there, and also jumps around to all the other SPS, but likes the candy cane frag the best. Yeah I know the nitrates are way too high, I'm doing just about everything I can think of to reduce them. Cutting back feeding, water changes, etc. My DSB isn't doing its job well enough I guess. Anyway I noticed the bleaching last night, its a bigger spot today and in more places, all of them on the rim. Would nudis start at the rim or start eating anywhere? I've had this cap since april and its dobled in size, in fact its the best growing coral I have, this bleaching is really making me scratch my head. Going to try an iodine dip right now. Thanks guys for your responses.

 

[dustin_P74]

hoe deep is your DSB and how long has it been established? link on montipora eating nudis

 

[JAG107]

DSB is 5.5-7" and the top 2" was added 6 weeks ago, also 6 weeks ago I added a 10gal fuge w/ 4" of sand & chaeto/caulerpa, which is growing, lit 24/7. Thanks for the link!

 

[JAG107]

I'm not really sure it was nudis that affected this cap based on the outer area only being bleached, plus I think the yellow clown goby, blue leg hermits and red coris wrasse probably would have eaten them as there aren't many hiding places on this frag for them. I did an iodine dip just now for 10 mins, and moved it to a different spot in the tank which is about 4" lower than where it was, I'll look and see if there's any more bleaching tomorrow morning. Frustrating!

 

[Bifferwine]

Do you use RODI water? And how often/much do you do water changes? You may need to temporarily increase your water changes.

Also, using crushed coral substrate, bioballs, a canister filter, and flake or pellet foods are common sources of high nitrates.

 

[JAG107]

I use only RODI water, feed mostly frozen foods and a small pinch of formula 1 pellets daily, lately I've been doing two 10-gallon water changes weekly, have a 6" sand bed with no bioballs, canister or crushed coral. 10 gallon fuge has a 4" sand bed also. I'm going to start reducing feeding, also step up the water changes to 15 or 20 gallons twice a week until the nutrients are under control. Weird, all the other corals are growing and have great color, just poor polyp extension on the acros.

 

[daugherty]

what do you have for light?

 

[JAG107]

My lighting right now is x2 250w 20,000k DE halides, x2 65w 10,000k PC daylights, x2 65w PC actinics, and I had the cap about 12 inches below the fixture, fixture being about 4 inches above the water level.
I don't think this is RTN as the bleaching is moving slowly, about 1/16" per day so far, but it looks like its still spreading. The iodine dip must not have done much. I broke off the bleached areas yesterday after the dip down to where it meets the living tissue, but it seems like it's receeded some more overnight. I wonder when I'll have to start fragging this poor guy.

 

[daugherty]

try moving it down i think a monti is a lower light sps

 

[JAG107]

Moved it down 6 inches yesterday. But it seemed to really like where it was since I placed it there in april, became a much brighter green and doubled in size. I'll see how it likes the lower position, also it is now in partial shade from the halides as it is directly under the piece of glass that came glued over the center of the tank. It's a little dimmer there b/c of salt creep and condensation that collects under it.

 

[ccCapt]

Yeah, they like lower light and high flow. Mine is on my sandbed.

 

[JAG107]

looks very nice, capt! I'll lower mine slowly and see what happens.

 

[yote]

Jag,Can you get a pic of the monti and the bleaching?

 

[JAG107]

Hey Yote, the pics are the initial post, I circled them in red. Yesterday I broke them off along with some of the living tissue. It hasn't really bleached much today, actually its really hard to tell since it's on the rim, which is a good sign I guess. I'll take some more pics in a couple of days and post them for comparison.

 

[yote]

This is just a stab in the dark.But I'm guessing that the lil goby is causing the bleaching by keeping the polyps closed a lot.

The pics did load for me when I first read the thread.Bout time for new puter I guess.

 

[dustin_P74]

yote ill build your computer for you if you buy the parts

 

[Bifferwine]

This is a stretch, but it could be the nitrates. You said yours were in the 20s, which is borderline for corals, but usually harmful enough to SPS. If I were you, I'd try stepping up the water changes for the next couple months.