Lighting for a 30" tall column...?

[insomniaclush]

I just picked up a 47 gal column tank measuring 20”x18”x30” and was trying to find a lighting fixture suited for this tank. I will want to grow some dwarf hair grass that I have leftover from another tank and some Vals, Anubias, Ferns, etc..etc... I was thinking of keeping two or three Peacock Cichlids in here with various other compatible fish. A tank with these dimensions, how would one figure how much wattage and whathaveyou would work best?

[eklikewhoa]

Re: Lighting for a 30" tall column...?

With that height I would have to say you will need something metal halide....also dwarf hairgrass and peacock cichlids will not work together, actually just about any cichlid and foreground plants will not work well.

[Mzungu]

Re: Lighting for a 30" tall column...?

Lots of wattage, I would say. I agree with ek, metal halide would look great on such a tank, if you can afford it. You can also get power compacts. They make a 20" 96W fixture, and Current makes a few different 20" fixtures.

[insomniaclush]

Re: Lighting for a 30" tall column...?

Gotcha,
nix the grass...! Nevertheless the rest of the plants would be
low light and wouldn't a MH be a little overkill or because of the height
should be kosher...?

[insomniaclush]

Re: Lighting for a 30" tall column...?

Lots of wattage, I would say. I agree with ek, metal halide would look great on such a tank, if you can afford it. You can also get power compacts. They make a 20" 96W fixture, and Current makes a few different 20" fixtures.

True, I see a couple of Currents that might could work such as that 40x2 CF.

[eklikewhoa]

Re: Lighting for a 30" tall column...?

IMO the penetration of the PC lighting would be limiting for foreground....having had the 96w pc on my 20g High.

With the low light plants you could get by with the 150w MH pendant if you go with a hanging pendant and keep it high off the tank.

[Hanson77]

Re: Lighting for a 30" tall column...?

I'd have to agree with EK on the PC lighting not being enough for that height.  I know the whole gallons per wattage debate is going to come into play sooner or later but I would go with MH as well.  I am having lighting issues on a 20" tall Oceanic with PC lighting.  It's great if your tank isn't deep but that's not your case at all....it's crazy deep.  You might want to step up to the 24" PC fixtures to get more wattage.

[insomniaclush]

Re: Lighting for a 30" tall column...?

Ok
if I were going to use a 150w or even a 70w MH,
how long could I run it w/o heating and algae issues?
I've never used a MH before and from other docs across the net
I've read stating only use them max for like 6hr per day. I'm hoping
to run the lights @least 10hr day...

[eklikewhoa]

Re: Lighting for a 30" tall column...?

I would go with the 150w.....the tank depth is your enemy with this tank.
If you plan on running open top and have ambient temps decent then you shouldn't have to worry about heat issues.
With the algae as long as your parameters are in check you shouldn't have a problem with it....I ran a 70w over a 5g and it did good but I ran co2....you're at a lot less.
With MH a little goes a long way as far as photo-period but I would start at 6hrs and work up to about 8hrs max....if you are trying to stage it so you can see it when you leave for work and when you come home or whatever just do a split photo-period of half and half.

[Hanson77]

Re: Lighting for a 30" tall column...?

Are you home to view 10hrs worth of lighting?  I have my lights come on at 2 pm and then go off at 10 pm.  I have the blue lunar lights come on at 10 so that there is a little light in the tank at night.  There is really no point in running lights when you aren't there to see them....just my two pennies worth.  If you really want to see that much light in the tank for that long, you could go with one of the more expensive fixtures that has both T5 and MH.  You could then stage the T5's to come on earlier than the MH to really simulate a day's worth of lighting.  Run the MH for the 6 hours that EK spoke of, shut back off and then the T5's would take back over.  You can find those fixtures that have been refurbished by Current USA on Ebay for about half the price of new if you do a search for Metal Halide.  This is a much more expensive route but it would serve your purpose 100%.

[eklikewhoa]

Re: Lighting for a 30" tall column...?

Or you could hit up Charles and see if he can get one of those Odyssea fixtures....they are dirt cheap compared to others in the same configuration.

[Hanson77]

Re: Lighting for a 30" tall column...?

The Odyssea fixtures come with PC lighting and you can get them for about $200 on Aquatraders as well as Ebay.  Just make sure it's one of the newer versions with an electronic ballast and not the infamous magnetic ballast.  I thought about going that route and just upgading the ballast for the MH.  If you read a lot of the saltwater forums people are having decent luck with those cheaper fixtures.  Now grant it, you may get a lemon here and there but for the most part, they aren't that bad.