semi-off-topic loghting and coral question.

[Tanstaafl]

I have a pair of 70w HQI 10,000k Aqualine lights in my 55g. I know it's not a nano, but I put in a 7" deep sand bed to simulate a 10g tank and have a water depth of only 12 inches. I went this route so I could save money on electric bill and keep the light intensity as high as possible. so I was wondering if the lighting would be comaprable to a 10g since the water depth is about the same? or are my calculations a little off?

 

So I was wondering what kinds of high light corals(sps) and clams would thrive in the tank. would acropora do well? how about T. Maxima clams? I tried to get help at other places but none have much experience with the small 70w HQI lights in their tanks , so I thought I'd post here as I see a lot of people use them here.

 

also can I get a list of what kinds of high light corals have you had experince with, and how well did they do? Did they stay alive, grow well, or lose any coloring?

 

Thanks in advance

-=Mark=-

[Fant]

Couple factors here, where exactly are the bulbs positioned. How high above the water line are they. If you concentrate the higher light corals to right underneath the bulbs, you would be ok. But the farther away you get from the lights. Not just vertically but horizontaly as well the light decreases. You could probably keep some higher light acros very close to the bulbs, but not at the bottom. But lighting isnt everything for acros you need the water quality and stability. so it really depends on how well your maintaining your system. You would have been better off with at least some 175 single end lamps. they dont cost that much to run.

[Tanstaafl]

Originally posted by Fant

Couple factors here, where exactly are the bulbs positioned. How high above the water line are they.

 

I spaced the bulbs evenly across the hood at 16 and 32 inches on my 48 inch tank. The bulbs are located about 12 inches from the surface of the water. I am planning on putting the bulbs in pendants this weekend. I seen the DIY 70w HQI pendant and I'm gonna try that out to help direct my light better.

 

If you concentrate the higher light corals to right underneath the bulbs, you would be ok. But the farther away you get from the lights. Not just vertically but horizontaly as well the light decreases. You could probably keep some higher light acros very close to the bulbs, but not at the bottom. But lighting isnt everything for acros you need the water quality and stability. so it really depends on how well your maintaining your system. You would have been better off with at least some 175 single end lamps. they dont cost that much to run.

 

I run an Aquadoser to keep my system topped off and have kalkwasser I will be adding. I do weekly 10% water changes. I may upgrade to 175w bulbs. but not until leter this year if I decide to do it. The upgrade shouldn't raise my bill more than $10. I think I can squeeze that into my budget. or remove something less important from it:)

 

Thanks for the help.

-=Mark=-

[Fant]

Dont forget the glass shield.

[Aiptasia]

Well, you don't mention how much LR is going to be in the tank, so calculating the water volume is going to be a bit tricky. I'm going to provide you with a link to a calculator that will help you determine the water volume of your tank (provided you also know how much LR is going to be in the tank). It does take into account the depth of your substrate as well:

 

http://www.garf.org/calculators/TankVolume...eCalculator.asp

 

140 watts of light over a 55g. tank probably isn't going to be enough to support a lot of light hungry corals. As Fant spells out, a lot of P.A.R. (photosynthetically available radiation) is lost with every inch of distance between the bulbs and the substrate. With 7" of substate, you're still looking at 13" of depth in a standard 55g. from the substrate layer to your glass canopy, and if they're another 12" above that, that's roughly two feet from bulbs to substrate layer.

 

For example, I have 130 watts of mixed 10,000k and actinic 03 light over a 20g. tank with a 6"plenum/sandbed and i'd say I could probably use more light for really light intense corals. My bulbs sit right on top of my tank (i'm using compact fluorescents so I can get away with this, much less heat than with HQI lights) right over the glass canopy, so there's 7" of depth from my bulbs to the substrate.

 

Your post was asking about keeping some really high light corals and clams, so the more light you can throw at it, the better if those are the species of animals you want to keep. I'd definitely up the lights to two 175w. MH bulbs, or even go so far as two 250w. bulbs provided you have good ventilation and/or a chiller for the tank water.

[Tanstaafl]

I picked up the pendants today. They have glass shielding already, plus the glass top on my tank. I seen in the DIY article that someone has called Regent about the glass and they claimed that it is UV treated glass on the pendant. not sure if it covers all of the pendants though as I seen the shop light fixtures have a UV treated stamp on the glass itself. but the flood light pendant I bought did not have any stamp? anyway... I figure between the two pieces of glass that it should be plenty of UV protection for the fish.

 

I have about 35 lbs of LR in the tank so I figured I had about 40g of water total, counting my 10g converted into sump/refugium. I used the calculator and it said 33g for the tank. and I usually have about 6-7 gallons in the sump. although I don't think the watts per gallon theory really applies to my tank as it is so much more shallow than an ordinary 55g, let alone a 40g tank. of course I don't think the watts per gallon is very accurate for any tank. just too many varying size tanks with similar tank size. That's why I came here for help. I figured in my unprofessional opinion that a watts per inch of water depth would be a more accurate application and since most nanos are shallow I would get a better idea of what would work.

 

also with the floodlight pendant I can adjust the height of the light and get it closer to the water, and then be able to move it out of the way to do maintenance on the tank.

 

I noticed a lot of people have their pendants about 4-6inches above the tank? do you think that would be a good height for maximum lighting?

 

Thanks again for all your guys help. It is much appreciated.

-=Mark=-

[Tanstaafl]

also on venting the pendants. how much would be enough? I want as few holes as possible. Plus I've read that the MH lights like to run a little warm and they perform better hot than cool. being in that tiny box though, it may need a few holes to keep from getting too hot. I'm sure they don't like being too hot either.

 

Thanks again

-=Mark=-

[2hip2Bsquare7]

Be careful!, with a sand bed that deep hydrogen sulfide gas can build up and then be released killing your whole tank!

 

Don't get any worker fish that will dig around too much in your sand bed.

[Aiptasia]

Originally posted by 2hip2Bsquare7

Be careful!, with a sand bed that deep hydrogen sulfide gas can build up and then be released killing your whole tank!

 

Don't get any worker fish that will dig around too much in your sand bed.

 

H2SO4 isn't likely to build up in a jaubert style plenum bed as long as it's well maintained. Nonwithstanding, since plenums essentially work like a septic system, I have made modifications to it to make it a super plenum (re-read my original post about the mod to the plenum plate) so that I can drain off the dead water space under the sand bed every six months or so. That will keep the anerobic bacterial colony healthy and keep it from fouling. Plus, the top layer of the substrate is GARF grunge, which is chock full of worms, shrimps, starfish and all kinds of god knows what else. It's essentially mashed up reef rock mixed with live sand. If you haven't seen it yet, it's the coolest stuff on earth for your substrate. Check out www.garf.org for more info.

[Tanstaafl]

Originally posted by 2hip2Bsquare7

Be careful!, with a sand bed that deep hydrogen sulfide gas can build up and then be released killing your whole tank!

 

Don't get any worker fish that will dig around too much in your sand bed.

 

the sandbed ecosystem should keep the hydrogen sulfide gases low in the system. hydrogen sulfide is horrible smelling and would stink up the whole house well below toxic levels. you would literally need to flip the sand bed upside down for it to be strong enough to kill everything. Just digging in it wouldn't release enough to do anything too harmful.

 

bummer... I was gonna point you to the sand bed articles but I lost all my links in my computer crash. and dummy me don't make backups.

[Aiptasia]

Yep. H2SO4 is a bad gas. Who needs swamp gas in your tank?

 

By employing the live sand/super plenum system, I should be able to keep things healthy down there. Somewhere I have a link to some albert thiel articles on this method but I think thiel charges $$ for people to access his site now. Bob Goemans also has written a plethora on live sand/plenum/deep sandbed systems. He'd be another good author resource and he writes for F.A.M.A. all the time.