Need help with Lighting questions... Please Help!

[sacs4010]

I have another thread, but I did not get many responses. I am hoping this one will. I need some help. I have an All Glass 29 gallon marine reef tank set up. I am buying a 150 watt 10,000 metal halide with two 65 watt attenic (I know I am spelling this wrong) and it will be six inches above the tank. What do you think? Please let me know ASAP. Thanks for the help and I hope to meet some of you next Saturday at the PSAS meeting.

Bradley C Sacs

 

[sacs4010]

Oh yeah...

I forgot to tell you my concern. I am concerned that the light will be two close to the top of the tank. PLEASE let me know what you think.

Bradley C Sacs

 

[Witfull]

the problem with halides over small tanks is evaporation. due to the size, the salinity will fluxuate between top off, even doing top offs daily, on a low humidity or warm day...you could lose well over a gallon a day. on larger tanks this isnt a prob, but on small tanks this could raise salinity to above 1.030.

another concern is heat. halides produce alot of heat, this will cause evap, but we have covered that, but water temps could easily go above 88* and this is a major concern. to help with heat, fans will cause evaporational cooling,,,,,but refer to issue 1. quite a quandy isnt it..and reefing is supposed to cure stress....lol

 

[sacs4010]

Well...

Well as of evaporation, I am able to check my tank everyday. So I do not think it will be a problem. I had a 15 gallon tank that I put a tetro fit compacts on, I think they were about a little over a hundred watts and they were right on top of the tank. It was an eclipse set up. It did very well. I am also building a custom glass lid that fits around my equipment and tank about 90-95%. This will also help with the heat. What do you think now?

Bradley C Sacs

 

[sacs4010]

and...

I am also having two high powered fans installed in my lighting system. Hey, if it does not work I will just down grade to just compact floresant (I cannot spell). Just need to make sure I could sell the one I am getting. I just want the most natural of the light sources and the best.

Bradley C Sacs

 

[plumber_bob]

If the fans are blowing over the water at all you will have lots more evaporation.... But it sounds like they are just being installed to keep the halide cooler.

 

[sacs4010]

Hey, Plumber Bob!

I stopped in your shop a couple of days ago. I could not stay, I was working. Anyways, yeah they are mostly just for the lights themselves. I just wanted the most natural lighting possible. If I get enough people on here saying that it will not work, I will change my idea and just get compact fluorescent system with night lights. If you have anyone else who could help, please let me know. Thanks again for the help.

Bradley C Sacs

 

[Witfull]

the problem with a lid is that yes it will reduce evap, but lock in great amouts of heat,,,,ever put a lid on a boiling pot?. i dont mean to sound sarcastic ,,,just using an example, but halides throw off more heat than PCs.

 

[sacs4010]

???

I was told from other sources that not having a lid will make it worse. By not having anything to block any of the light. Like having a tourch right on top of the water, instead of having a lid.

Bradley C Sacs

 

[sacs4010]

???

OK Wittful. What kind of lighting do you suggest? PlumberBob?

Bradley C Sacs

 

[MtnDewMan]

Bradley ... I don't think anyone here is saying what you want to do is bad. I really haven't seen anything indicating that they want you to change your lighting scheme. They are just pointing out things you need to consider when having metal halides on your tank.

For what it's worth, I had a 29 gallon tank with one 250W metal halide bulb fired off an HQI ballast with two 75W VHO actinics as supplementation. I had a couple of fans that would blow into the canopy to keep the tank temperature from rising too much. Of course there was a lot of evaporation that came along with that. All it meant was that I had to stay on top of water top off to keep up with the evaporation. It worked great. Corals love the lighting, the tank didn't get too hot and all was well.

Here are excerpts from my old web site when I had the 29 up and running:

I am still using the HQI ballast but instead of the mini pendent with the double ended bulb, I have gone to the German 250W 10k AB single ended mogul bulb. It is not as intense as the double ended bulb but more intense because I am using the HQI ballast. I like this combination the best and am sticking with it for a while. The color is still very crisp and the light does not seem to overwhelm the tank anymore like with the double ended bulb.

The canopy is cooled by two Toyo fans. One is rated at 78 cfm, the other for 96 cfm. These are amazingly quiet fans and I highly recommend the Toyo fan for anyone wanting a quiet canopy cooling system.

Hope this helps. By the way, the bulb was about 7" off the top of the water.

 

[plumber_bob]

I've seen many of the HQI 150w Metal Halides on your size tank.. Personally I would keep it that way. Just make sure there is no lid so that water can evaporate.... Maybe even hook up a little 5 gallon bucket or something next to the tank and get a auto top off system... They are affordable and work off of vacuum so they are reliable....
In all honesty I would keep the 150w halide, if you aren't worried about spending money then go that route. It is going to look awesome I highly recommend it.

 

[sacs4010]

Thanks!

Thanks. I am not worried about evoporation so much. I am worried about heat. I do not have any room for a chiller and I am worried about UV. How far did you have the lighting from the tank? See, I am only having it six inches from the top.

Bradley C Sacs

 

[sacs4010]

HA HA HA!

You know. I have been told by all my friends that are into the hobby and the people who I am dealing with at Blue Sierra that I cannot plan a tank. I mean, you have to plan it of course. What they say is that no matter what, you never follow everything by the book. A tank is succelful by trial and error. I am a little OCD (over compulsive dissorder) and this is hard for me. I would like someone to say, "This is how you do it." HA HA HA!

 

[plumber_bob]

As long as the 150w halide has the UV protectant glass peice then you are fine.... In reality even if the light was a foot off the water if there were any signs of UV it would still effect the tank.

I never had problems with heat in any of the other tanks.. The heater just didn't click on as much, which could be a good thing.

 

[sacs4010]

?

Now I am hazy about the lid. I need a lid. Some of the fish I want are rare and they are known to jump out of the tanks and I hear opposite opinions about having a lid or not. Hmmm?

 

[plumber_bob]

Ok, this is what you are going to do!!!!! You are not going to keep a lid on the tank; however, if you do get a fish that tends to jump put it on and leave it on for awhile (Monitor your heat fluctuations.) Once, you feel comfortable that the fish is not going to jump out, take the lid back off and leave it off until you get another fish that jumps.

If you get any kind of Jawfish they have a tendency to jump a lot, so I highly recommend staying away from those. You may get lucky and not get one that jumps, but in the wild they tend to swim up high away from their hole at night.

 

[NaH2O]

IMO, leave the lid off. I am concerned about the amount of heat you would get, as Witfull stated. If you are only afraid of fish jumping, then try a piece of egg crate over the top instead of a lid. It will keep the fish in, yet won't trap the heat.

You've been receiving some great advice, so far!!

 

[jks1]

I agree with above. I have a 29g with a 150W MH and 2 15W actinics in a hood. The MH is protected by a UV glass bottom on the hood. This set-up is sitting about 6" from the top of the water, but the tank is open topped. There is only one fan installed in the hood. I drip Kalk 24/7 to control evap and am currently dripping about a 1/4 gal a day. It gets more in the summer. I keep the tank temp at 79.5. HTH

 

[bradreef]

I have also had a 20 gallon but I had a 175 halide and a 55 watt pc over it. After about a week I had to install a fan in the hood because the temp was fluctuating more than I wanted. After I did this It worked fine. It was about 8-10 inches from the water. I like chucks Idea of the 250 watt though. I would use the eggcrate top If you are going to have a top at all.