Why don't my corals grow?

[TonyB]

I had 10k bulbs over the tank for a while when it was first set up. About 18 months I guess. Growth was pretty dismal then but I chalked it up to being a new tank. PAR readings were close to what I get now with the Radiums which is around 250 at the bottom.

I have 20 fish in there. I don't think it's low bio load :)

Yellow tang, purple tang, copperband, 5 anthias, ocellaris pair, yellow wrasse, mystery wrasse, purple velvet wrasse, laboutei wrasse, randalls goby, pink spotted goby, solarensis wrasse, cleaner wrasse and a virgate rabbitfish in the frag tank.

 

[roshi719]

with that many fish, I would say just feed a little heavier. Fish poop is the best acro food!! If tht doesn't do it then try doseing some aminos.

 

[TonyB]

Sounds like a plan. Thanks for all of the help!

 

[TonyB]

I wanted to update this thread since I changed the photoperiod. It's been a week and believe it or not I have already seen some changes. A couple of the tabling corals and monti caps are showing some signs of bleaching. A handful of the smaller colonies that were stagnant are showing signs of growth. There are a few corals in the frag tank that have browned out quite a bit. Not sure what to think of this yet but I'm going to chalk it up to them adjusting. Figure that's a good excuse for now :)

 

[2FarNorth]

I take it your photoperiod is 9 hours? That is a large jump from the 2 shorter periods... I would start off slow, maybe 3 hours for 3-4 days, then bump it up an hour every couple days.... The most I've ran my halides are around 7 hours.... Actinics on for almost 12....


Sounds like they are starting to get shocked some from the light.....

 

[ahayes13]

i would agree with 2farnorth... you went from two shorter periods to one increased photoperiod. i would have acclimated them to the new schedule. which you could still do.
if your original photo period was at 4 hours then start with 5 hours. and let it run that way for at least a few days and then bump it up another hour and so on. til you get to your desired photoperiod. this should acclimate all the corals correctly and elimate any further bleaching....

 

[Henry C]

Do you dose your tank with any supplements like B-Ionic or Randy's 2 Part ? Do you add any additives like stronium or drip kalkawasser?

 

[FaviaFreak]

sounds like photoinhibition

 

[Old School Reefer]

I also noticed that you're running 20K bulbs. 20K bulbs produce great color but noticeably less growth IME.

When it's time to do your next bulb change try the Ushio 14K. Good color and better growth overall.

 

[six-line]

Tony,
How the tank looking it been about a month any improvement?

 

[Anonymous]

Do you have any softies in your tank? They can slow the growth of hard corals.

How so?

 

[makingbubbles]

dude dont know whats going on with your tank, but that is slow. Im running less than 4watts per gallon pc light and my frogspawn went from 2 heads to 4 heads in a month and a half and that was under bulbs that were over 2 years old.