Metal Halide Questions.....

[bullhead]

what size metal halide woud I want to use ,wattage wise for a 50gal.(u.s.)tank.I think its 18" deep. Can I use a a single bulb fixture or do I have to use a double fixture to properly illuminate the entire tank.what is the best bulb iyo for plants?no paticular type,I wolud like to shot for 4 watts per gal.If I raise the hieght of the fixture does this lesson the amout of wattage availible to the tank?

 

[bullhead]

No one has any suggestions?

 

[BHornsey]

Is this a planted or fish only tank?

Personally, I wouldn't go for more than a 70w MH.

I have a 30 UK gall planted tank over which I placed a 150w. It drove plant growth to crazy levels.
For a fish only tank you may get away with brighter but it may drive an algae bloom.

 

[bullhead]

Is this a planted or fish only tank?

Personally, I wouldn't go for more than a 70w MH.

I have a 30 UK gall planted tank over which I placed a 150w. It drove plant growth to crazy levels.
For a fish only tank you may get away with brighter but it may drive an algae bloom.

Planted tank,high light plants and driftwood with philadendren on it above the water surface.What distance from the tank surface? I've heard evrything from 8" to 24".Further from the tank ,the weaker the light penatrating to the bottom,is this right?

 

[SkiFletch]

About 12" seems to be the optimal distance from the surface for halide lamps. With a 4 foot tank though you'll NEED a dual setup. Most halides struggle to cover more than 2 feet of length. I'd go with a dual 150 or dual 175 watt setup.

 

[bullhead]

About 12" seems to be the optimal distance from the surface for halide lamps. With a 4 foot tank though you'll NEED a dual setup. Most halides struggle to cover more than 2 feet of length. I'd go with a dual 150 or dual 175 watt setup.

Yeah,after doing more research I'm looking at a dual 175 watt retro fit kit.By the way thanks for the help.

 

[BHornsey]

Just a word of caution. I have a 30 UK Gall tank over which I hung a 150w MH.

It does work but it drives phenomenal growth and, if there's any shortfall in ferts or CO2, algae is gonna be the result (beleive me, I found out the hard way )

Provided CO2 & ferts are kept steady, you will still get nice growth with lower wattages. I replaced my 150w with a 70w and since then, everything has settled down; I still get good growth, just slower. It's nice to be able to go a week without needing to be up to my armpits in water, pruning out excess growth.

My advice is still, go with less light. A pair of 70w would be more than adequate. If you need more than my word, ask Plantbrain. It's one of his mantras

 

[bullhead]

My advice is still, go with less light. A pair of 70w would be more than adequate. If you need more than my word, ask Plantbrain. It's one of his mantras
[/quote]


2 - 70 watts would give me approx. 2.8 watts per gallon,I'm not sure if that would give me enough to grow the plants I'm planning on.I would like to use either glosso or dwarf hair grass in the foreground,blyxa japonica or whorled pennywort in the mid ground and maybe some sort of vallisneria in the bacground.I'm not so much worried about the vallisneria but the others would benifit from the extra wattage right?

 

[SkiFletch]

Its probably a question better suited for the planted section. My gut instinct tells me to go ahead and use the 70s though. You'd be surprised how much PAR a decent quality plant MH can put out...

 

[bullhead]

Sorry to be off subject Thanx for the advice and I think I will go with the 70's.

 

[SkiFletch]

Sorry to be off subject Thanx for the advice and I think I will go with the 70's.

lol no need to apologize. Just trying to help you get the issue in front of a more targeted audience over there

 

[BHornsey]

I have 3 70w MHs over a 6' tank.

Everything grows, it's just nice and steady.

Cabomba and other fast growers take about 2- 3 weeks to grow to the waterline, whereas with more light, it could do it in less than a week

The supposed high light plants still grow in there. Provided I keep CO2 nice and stable, I have few problems.

What type of fertilizer routine are you planning, EI or low tech?
Lots of useful info for you on the planted forum