Montipora digitata question

[Delphinus]

I thought this stuff was supposed to be like a weed?

I'm obviously doing something wrong here. I've got a frag going on, what is it, going on three months I think, and it hasn't done a dang thing in my tank. Not a millimetre of growth, no encrusting at the base, not even polyp extension. It just sits there in perfect stasis.

Ca=400ppm, Alk=4.0, NO3=0.0.

My guess is, the difference must be either something about the water current, or the lighting. Mine sits underneath a 250W halide (6500k); should I perhaps move it away from the bulb or even into a bit of a shadier area?

(However .. if it is perhaps the light is too much, wouldn't I see polyp extension at night?)

Hints/tips/advice? (please and thank you)

[Jacoda]

Hmmm.......I got my frags from Darren about a week ago and it's been growing like weeds, FYI I only got VHOs.

[Aquattro]

Tony, if you can figure out how you get this stuff to NOT grow, let us know!!

[BCReefer]

I got a frag from Darren last year and for the 1st 4 months it hardly grew at all. I did some new aquascaping and it was move to the side of tank with a little more water flow and a little less light and it has tripled in size in the past 2 months.

HTH
Patrick

[Delphinus]

Thanks for the replies. Brad, that's an easy one, if you don't want it to grow, give it to me.

The only things I can think of, are:

1) My values are not what I think they are (using Seachem test kits .. thought they were OK, but who knows). I am starting to doubt my values, because I don't even have coraline in this tank (6 months old). Almost entirely none whatsoever. Maybe a wee little spot here or there. I think about 3 spots of 2mm coraline patches on the glass.

2) It's a water flow issue. Tank is a 75g, flow is accomplished with two MJ1200's laterally opposed at either end, plus a MJ1200 running a spray bar, plus the sump return (have no idea what the flow is through that, though.) The sump has only been in operation just shy of a week though, so that hasn't been able to help until now. It seems that there is flow, but OTOH it really does seem a whole lot gentler than a lot of tanks I know.

3) It sits directly under the Iwasaki, and it's on the top of the reef. So maybe it's just too much light for it's liking.

I have other SPS, which HAVE shown some evidence of growth (Montipora capnicoris, mostly, some some acros, a small birdnests ... wee little things mostly). Not as much growth as I would like, of course, but there is some (about 2-3mm per month. When I say "some, but not much" I really do emphasize the "not much" part! :( ). So I'm thinking there is something particular about the environment that is particularly objectionable to the M. digitata.

Maybe my nighttime temperature is too low? It goes down to about 24.5 at night (76F I think) and daytime highs are usually 26.5 (79F). yesterday it was >30C outside and the tank hit 27.5C (82). Is this too "cool" maybe??

[ 12 July 2002, 09:11: Message edited by: delphinus ]

[Aquattro]

Tony, I've found that it doesn't matter where I put it. I have some directly below the 400w MH, some on the sand, some in no current and some directly in front of the powerhead. It all grows like weeds. I've also found it not too dependant on water parameters. I've sold some to the LFS and it even grows in their tank (you don't want to see their tank). If you were closer I'd deliver it to you on a weekly basis. I've been trying to give it away. I'm almost at the point of just throwing it in the garbage!!

[One_Divided]

I agree with brad, current and light don't seem to be all that important with digitata. I saw a 1" brown digi frag grow to a 5" colony in about 3-4 months. It was in a lowly corner of my tank with little current. I managed to pawn it off at the lfs for some credit.

IMO, the only thing it can really be is a water chemistry thing.. You either have something in the water it doesn't like, or you are missing something in the water..

[Delphinus]

Any suggestions of things to look for?

[Canadian Man]

Call the city water and see a list of all the things nasty in ourwater.
Maybe you should start using your ro.
just a suggestion that i pulled out of my A@#
but who knows!

[Diomedes]

Did you say your alkalinity was 4.0? This might sound stupid but is that in dKH? Because if it is in dKH then it should be around 8.0 to achieve maximum calcification. Also your M. digitata may not have enough trace elements (including mainly strontium and magnesium) that it needs in order to lay down calciferous layers. They need strontium esp. for rapid growth. I use only Salifert test kits (which I Slowly, Slowly aquired after months of eating Kraft Dinner) and have had a wonky reading or two come out of a Seachem IMO. I don't recommend dumping tons of trace elements in though...that can cause more problems than it solves. What are you using for maintaining your chemical levels? (Ca, Sr, Mg, I etc?)

Stephen