Large colonies stn from center out

[Bustyraker]

I have or should I say had a large colony of green slimer that last week started to stn in the center and I ended up having to cut it up to save it. Today I noticed my favorite acro is doing the same thing! I'm sure I will have to cut it up also but I don't want my entire tank to go down the toilet. My nitrates are 0 with salifert and nyos kits, po4 is. 04 with hanna. Alk 8.2 and calcium 425 ish. I haven't added any new corals since October and the only thing I've changed is I increased my photoperiod by a half hour 2 weeks ago. I have a 105 gallon with 2 g3 radion pros which have been at 100% on radiant color for near a year now with awesome growth. Just can't seem to think of what might be causing this.

 

[Tyler_Fishman]

I lost an entire seriatopora frag from Stn, I could only salvage a tip, I believe it may have something to do with either lighting or irritation, are you sure you don’t have acro crabs? They like to make a little white area where they hang out, I know it’s not really a factor, but always check, have you added anything? Dosed anything? Changes flow? Did you check for pests?

 

[jwshiver]

If it's in the center my guess would be a lack of flow.

Also have you checked your iodine level. I know iodine has a lot of debate on its usefulness but my personal experience has been that I haven't had any STN or RTN since I have kept my iodine levels up.

 

[Bustyraker]

If it's in the center my guess would be a lack of flow.

Also have you checked your iodine level. I know iodine has a lot of debate on its usefulness but my personal experience has been that I haven't had any STN or RTN since I have kept my iodine levels up.

I have 4 mp40s at 100% in a 4 foot tank. Plenty of flow. Iodine is a good idea though. I will test and dose tomorrow.

 

[Scorpius]

I'd cut back that half an hour you added to your photoperiod. You'd be surprised what a little change can do to a system. My Green Slimmer is my canary in the coal mind so to speak. When Mr. Slimmer aint happy, aint nobody happy. lol

 

[ajcanale]

Have you considered that there might be pests? specifically AEFW... Given that the damage is more center based on both and that based off images there seemes to be drastically less PE the closer you get to the center. Just my first thought based off the info and images provided.

 

[Graffiti Spot]

Yea I would check for flatworms. Green slimers are rock solid in any tank I have had. Also were very resistant to flatworms so maybe you could have had a swing somewhere a few weeks back if you don't see any. If you can't dip baste the bad looking corals for a few weeks to see if anything ever comes off. If you baste once it doesn't mean you don't have them. If you do it could be only a few and may take time to grow in numbers.

 

[2Wheelsonly]

it would seem very odd that worms if introduced to the tank would attack the green slimer first (if thats truly the first one you're having an issue with). Have you had any recent growth spurts? Nutrient requirement change? Maybe more water change necessary to keep up with trace demands?

I'd WC and scale lights back to original setting. Look at doing a deep clean on power heads too; could be flow limiting over build up (if dirty).

 

[Rakie]

I have 4 mp40s at 100% in a 4 foot tank. Plenty of flow.

Not necessarily. Ecotech pumps are extremely directional, additionally, most people consider an mp40 to max at about 2'

I think still even in this day, nothing beats a Sea Swirl.

 

[markalot]

Are you sure nothing else changed? The only things that have harmed my green slimer are a rapid drop in PO4 back when I was worried about such things and a big KH spike from 7.5 to 10. In both cases the slimer started to suffer about a week after the incident and only fragging saved it.

 

[jda]

Colonies are harder than frags. Flow has to change and sometimes the lights do too. Most people need to step their game up to keep colonies.

If the water quality is OK and you have no pests then I would look towards stronger, higher velocity flow that can penetrate the branches instead of just going around them. Shadows can also start to become a huge issue with LED as the only lighting - adding T5s can really help this. Your dead spots look like they are in the shadows, so definitely pay attention to this... this is most likely your issue, IMO.

The wideness of a MP pump moves a lot of water, but it lacks the velocity a lot of times to get in-between the branches of a tight acro colony. A true wavebox will wash water in/out of the smallest branches, but these need flow pumps as well. This is why a lot of guys with large acro tanks still use high pressure pumps on CLs with eductors or sea swirls where a tight, high velocity jet can get do more for a colony than a MP. The narrow output mouth of a Tunze is better at this, as well.