View Full Version : RTN with SPS

03-30-2011, 12:18 AM
So I've recently witnessed some frags I recently purchased go from beautiful to almost non-existent. The culprit...rtn...so all I've been able to figure out, through research and asking others, is there is no conclusive reasoning as to what causes this devastating disease (is it a disease? not sure) other than "stressful" conditions. And it's also happening with acros that I've had in the tank for a while. The only change is a new light fixture which I believe I've acclimated properly.

So does anyone have any thoughts on what causes rtn? Or what can be done to stop the effects? A while back I had a large hydno frag that started with rtn (it was just fragged that day and I brought it home) but eventually just stopped decaying and is now in recovery. Is this "stop and recovery" a normal process or does it usually end in the demise of the coral in its entirety?

So quick facts...
water parameters are spot on and consistent (main 4)
calcium and alkalintiy are checked on a normal basis - calcium is dosed; I do not attempt to adjust the alk. I was told that higher than natural sea water is fine but anything lower is dangerous (alkalinity represents a certain amount of carbonate in the water and there are no ill effects of high alk) I wonder how true this is...I'll get accurate numbers if necessary.

03-30-2011, 12:22 AM
How do you dose you Cal and what is your dKH & Cal levels at ?

I have read info that suggests higher dKH can be bad for corals, IDK how true that is.

How did you acclimate the corals ?

03-30-2011, 03:22 AM
When I dose the calcium, I usually just mix it in with water that I'm adding to top-off the tank. Sot it might get mixed in with a gallon or so of water and then is poured throughout the tank. I use Brightwell Calcion-P.

I try to keep my calcium around 420 and currently the alkalinity is sitting at 8.4. I am using the Salifert kits for calcium and alkalinity.

As for acclimating, when I acclimate new corals, I cut back the lights and float the bag for about 15 minutes or so. Then I'll fill a measuring cup with tank water and, depending on the size of the bag, add anywhere from a teaspoon to a tablespoon and slowly work my way up. This usually takes about 35-45 minutes. Then the coral is place on the bottom off-center and is slowly moved up, if necessary, as the weeks progress.

Recently I upgraded from a two-bulb t5 fixture to a 250W MH w/ 4 bulb t5 actinic (a huge jump!). So to acclimate the corals to the new light I purchased a roll of screening material. I cut the appropriate size screens and placed them on top of the tank underneath the light. Every week I would remove one layer. I started with four screens and now have none.

I have three frags sitting front and center, maybe 6-7 inches underneath the light. The hydno has a small area of what could have been rtn but it hasn't spread and I think it's been there from the start. I have an acro that has a beautiful blue coloring with great polyp extension and coloration. And then there's another acro...I bought this acro a while back and it "browned-out" under the two-bulb t5. Now there is minimal polyp extension, the brown is slowly going away, but it looks like the center has rtn. The acro is supposed to be white with blue tips. Under a black light, the tips still glow significantly. I'm just a bit worried. It appears the same thing may be happening to my Purple Godzilla acro as well, which sits much lower in the tank.

I have the other two frags which I recently bought and then they started to fall apart. This I can understand. There may have been problems with the original coral, or the frags may not have been given enough time to cure before being sold. But the other acros going from brown to colored to white has me a bit scared.

Wow that was a mouthful...

03-30-2011, 03:48 AM
Your dKH is getting really close to the low end of the safe zone. I notice a big improvement in my SPS when I started dosing daily and brought up my dKH to 9.6 and maintain my Cal at 400 to 420.
After using a weekly dosing approach (dosing dkh and Cal on different days) I starting noticing the corals (specially the SPS) would show a little stress the day after dosing. So now weve started dosing daily. I basically took the weekly amount of Cal and divided that by 3 and took the weekly amount of dKH and divided that by 4 so I could dose daily and alternate Cal and dKH. Ive listed the routine below:

Monday 3.5ml of dkh
Tuesday 3 ml of Cal
Wednesday 3.5 ml of dkh and dose of coral food
Thursday 3 ml of Cal
Friday 3.5 ml of dkh
Saturday 3 ml of Cal
Sunday 3.5 ml dkh and dose of coral food

Once I started this, my acros started to color up even more and has even started growing. I might be worth considering giving this a try

It sounds like you have really taken a lot of precautions acclimating the corals to the light so I cant imagine that as the cause of your troubles

The only other thing that comes to mind is your nitrate levels. I have read about SPS getting stress and dying once the nitrate exceeds 5ppm as SPS prefers pristine and stable water. That might be worth looking into as well. Ive read about acros turning to a darker brown when exposed to higher nitrates

Edit: I fogot to mention about salt. You could check to make sure your salt is replaceing trace eleiments like Strontium and Iodine. But I'm just grasping now

03-30-2011, 11:13 AM
Do you have any leathers in the tank and are you running any carbon? I added a large toadstool leather last year (12x12 inches) and within a day 2 nice sps colonies RTNed. One I lost completely and the other I still have a small amount left. I've since gotten rid of the leather buy now always run granulated activated carbon.

The only real way to at least slow it down or stop it is frag was good. I recently had a bought with slow tissue necrosis and I couldn't for the life of me figure out what it was, but in most cases if I cut out the bad sections it would pretty much stop. I think if finally nailed it down to being lack of flow. Some of my older colonies were growing to the point that they were blocking or slowing down flow to colonies behind them. So I moved around some powerheads and it seemed to have stopped it completly

03-30-2011, 02:47 PM
Cliff, great advice. I may have to try that out. And is 8.4 alk really on the low end? I thought nsw was around 7ish so anything above that should be fine (alk used to be double digits). Any recommendations for an Alk product?

Does anyone ever feel the need for a chemistry degree while maintaining a reef?

Labnjab, I do have two leathers. I have a kenya tree (about 4-5 inches tall and about 1 inch across) and a finger leather (4x4x4). The kenya tree is in direct flow from the protein skimmer and the finger is tucked in the back. If there's any potential that they may cause harm then they're definitely out. I'll do a trial for a week or so and place the leathers in the qt tank.

I do run carbon in the tank, perhaps not the highest quality but I do have it. I use Deep Blue Professional carbon pads. I have a small hob filter which is stuffed with these pads. Also I wrap carbon around the intake of the filter and around one of the power heads. I had actually planned on getting another power head today, coincidentally, to help keep things swirling since I'm still noticing microbubbles in the tank (which i believe are from the protein skimmer which has been running for a month or so)

03-30-2011, 02:58 PM
Almost forgot to mention...

The past two times I filled up the water containers, I went to two different places. The place I usually get water from is very reputable (the others are as well, and the one even more so than the original) and they have a brand new "state of the art" filtration system. Without getting in too deep with this, is it possible that using water from three different places within a month could have this adverse effect on sps? Just a thought...

03-30-2011, 03:36 PM
Does anyone ever feel the need for a chemistry degree while maintaining a reef?

:hmm3grin2orange: Yup !!!

I've always been told not to let the dKD drop below 8 for SPS. That always been the rule of thunb that I used. The fact that it is dropping leads me to assume your corals are consuming it so it could be a good idea to keep the level higher to ensure a strong supply for the corals. I've only tried one dKH addidtive which seams to work really well for me. Below is the product that I use:


03-30-2011, 05:10 PM
Actually his alk is pretty good. I've been hearing, and I'll try to find some more info, that higher alks actually hurt calcium intake. Between 7 and 9 is ideal. As long as it stays consistent I wouldn't try and change it. I keep our at 9 with a calcium reactor and get incredible sps growth.

I would also try to use a higher quality carbon in a reactor, like this one from bulk reef supply http://www.bulkreefsupply.com/store/1-5-pounds-half-gallon-premium-rox-0-8-aquarium-carbon.html especially with leathers.

Another thing, what are you using for flow and what flow are the dieing coral in? Flow is very important for coral, especially sps. Low flow can kill sps fairly quickly

03-30-2011, 10:20 PM
Flow is actually pretty good, well I thought it was at least. I had two Koralia pumps (240gph), small hob filter (100gph?), and a remora protein skimmer. I actually just added another koralia nano today, bringing the count up to three. I would figure that this is plenty of flow for a 20 long. Should I adjust the direction of the pumps and have them blowing directly at the sps coral? I have them set up now to bounce off the glass first.

As for the alk, I just picked up a two-part calcium and alkalinity additive that the store owner makes himself. I was told that 8.5 is where they keep their alk, and anything between 7 & 10 should be fine. So I'm going to go back to monitoring these levels daily and dose accordingly. I do like the idea of breaking up the dosing amounts and adding everyday. Probably a bit better for the corals.

Ha I have to laugh. I've heard so many times that saltwater is just as easy as freshwater. And keeping corals is just like keeping a planted freshwater tank. Boy o boy I must be doing something wrong...but if it were so easy it probably wouldn't be worth it. :22:

04-01-2011, 11:09 AM
That's not nearly enough flow for sps. Our frag tank is a 20 long which is 99% sps and with no rock, and I have 2 koralia evo 750 powerheads on a wavemaker along with a 500gph return pump, and still have dead spots no matter where I position the powerheads. If I had it full of live rock it would be even worse. I would position the sps close to the powerheads, or use larger powerheads

04-02-2011, 02:55 AM
Wow, I have to admit I didn't know they needed that much flow. Thanks for the info! :19: Currently all the sps corals sit almost in a straight line across the tank. I have one powerhead on each side blowing directly at each other with a thrid on the back wall helping out. After adding the third powerhead the other day I noticed a HUGE difference in flow. I was almost afraid the polyps were going to blow off! I may add a fourth or upgrade to a stronger powerhead in the very near future. Thanks again for the info! I also upgraded the carbon. I threw away the Deep Blue pads and got Chemi-Pure Elite. I would assume this is a step up from the pads. I was told it was good, but I guess time will tell. I love the help I get here! thumbs2:

I can't wait until I get the 33 long up and running; so much to look forward to!