MH Lights. Not sure I did the right thing.

[jasper24]

Well it has been about 2 months since I upgraded from a Coralife 130W PC over my 20 H to a Coralife 150W 20K MH. I have the MH about 7 inhes above the water and used the screen method over the course of a week and 1/2 to acclimate. Many of my softies (Ricordia, Zoanthids, Mushrooms) were still not looking to good so I set my 12G JBJ up with 48W PC and placed them in there. I used sand, water, and LR from my 20 to set the 12 back up. Within a day the softies have colored back up and look great in the 12. I thought that MH was the lighing of choice? All of these softies were towards the bottom of the 20 so I do not think that they were getting to much light.

[sulp]

I don't know where I read it but I definatley read somewhere that 20k bulbs were not recommended. Something to do with the light spectrum being bad for some corals. I really can't remember the exact jist of the article but I definatley remember reading to stay away from 20k. Maybe someone else will jump in who has a little more knowledge on the subject.

How do you like the color of the 20k? Is it really blue with the actinics on? I have 10k and was going to upgrade to 20k until I read the article. Now I think I'm gonna go to 15k.

[jasper24]

Anyone else on the 20K? Also what spectrum do you think the stock 48W JBJ Nano lights are? Thanks.

[mydogdylan]

I'd like to get more info on this also. I upgraded to a 75g tank and went from PC to halides. I lost several LPS corals in the transition. I'm using 20k. However, I have friends who use 20k and have had good results. but they primarily keep SPS.

[jimmy n]

In my opinion, if you plan on keeping softies only, why upgrade to MH? If they were doing fine under PC's, then stick with it. If you plan on LPS and SPS, MH is THE lighting of choice.

Jim

[gillies]

I second Jimmy.

[jasper24]

It was the clam Jimmy. Had to have a Crocea. Everybody said you have to have MH.

[Avi]

There's something else wrong, though I don't know what it is. You can't blame the 20,000K MH for the problem unless the soft corals were way up at the top of the rock under the bulb. If that were the case then I would say the soft corals were getting too much intesity even though the 20,000K didn't appear to be throwing so much. Where were the corals placed in the tank?

If they soft corals were all over the rock, high and low, and they didn't do well under the new MH, I'd have to conclude that you should raise the MH fixture up about three inches because it's just too intense where it is.

[anthony34]

I third that Jimmy, also keep in mind jasper Ricordia, Zoanthids and many Mushrooms do not like alot of light which would explain why they may not be doing so well, usually those corals you would want to put in a more shady area then in direct light of MH and as Avi say either raise your lights, or just rearrange your rock work. The MH are great choices but just try to keep some shaded areas to have LPS in and keep clams/sps in the direct light of the MH... the 20K deal is not a problem at all, I use 2x400 20k in my 90 SPS and clams love it, but LPS and lower light corals such as Mushrooms do not like it at all but I have nice shaded area I have made with rock work and it works out great.

[jasper24]

I am really confused now. All of my softies are / were off to the side of the light on the bottom. I posted a similar thread in the "lighting" forum and was told that the "PAR" rating on the 20K was no good and I was probably getting more light from my old 130W PC set up than I am now.

[anthony34]

its not that the par rating is not good, I would say that it is not as much par as say a 10k - 14K and actually most of the time corals open/Streach more to comphensate for less par that why I would not say its the 20k lighting so your lighting should be ok, I would look more toward placement of corals and/or parameters of the water itself to be sure you have all the needed nutrients ph/alk/mag and such.

[jasper24]

I appreciate the thoughts but it is not the water. Both tanks have the same parameters. I started the 12 with water from the 20 along with sand and LR from the 20. I dose a 2part in both. Parameters are below.

PH 8.1
SG with refractometer 1.025
ALK 10 KH
Calcium 430
No trites , trates, ammonia present.
Temp 80-81.5

Have 2 fish a small tank raised clown and a 6 line and they are doing great in the 20.

I may try a 10K just to see if it makes a difference.

[anthony34]

all looks good, just shocking it would be your 20k many use them with no problems including myself but hey anythings possible, hope you get it worked out.

[Chrisgriffith25]

I run 20ks on my 55g but they are 400w. Unless using high watt mh 20ks should be combined with another bulb off approx 10k for a higher par value. My advice would be to get a new bulb possibly a 10k, but the supplemental actinic would probably be desired/needed. I still feel that the 20k should sufficient for such a small tank though. Try to create a shaded area and place your softies there.