hi - i know MH is mostly used for planted or salty aquariums but what are the experts opinions on here of using them for an 18" tall cichlid aquarium ? the reason I think they might be cool is because that type of light tends to be quite vibrant and if the water surface ripples then the MH's make that reflect on the bottom of the tank any reasons why they might be good or bad ?

They be good! :bounce:

I like the white/blue type.

cons- expensive to run, as compared to t5's. they cost a bit too. and you'll probably need to have them suspended above your tank, if you are going for the look I think you are going for. No cover for that tank too, as the glass will not appreciate the heat. But im sure you know most of this :lol:

pheonix44 - no lids ? at all ? hmm, may be a problem as i have cats who like to swim, lol - how about having SOME cover outside of the main zone the MH shines directly over?

no cover as in hood but you could still have glass lids if you hang the light from the top of your ceiling?

no cover as in hood but you could still have glass lids if you hang the light from the top of your ceiling?

i was originally planning to make a wooden hood for the tank - then when i thought of the metal halide (its an arcadia series 3 with on MH bulb and two flouro's) i thought i might attach it to the underneath of the hinged hood lid somehow - if you think heat might be an issue i could ensure ventilation at the back panel of the lid and/or in the top too - and even put one or two cheap computer fans in the hood for added cooling. what do you think ?

sorry couldn't help you there but I've seen really cool tanks with their metal halides hanging and no hood - going for the mod/minimum look

sorry couldn't help you there but I've seen really cool tanks with their metal halides hanging and no hood - going for the mod/minimum look

i would love to go that look too - the cats would love it too - they would have their very own warm swing to lay on (and break !)

you can have a lid so fish don't jump out the tank etc. but what ive done in the past is gone for the rimless tank look, and risked the fish jumping ha ha.

MH's get really hot, so over time the glass can heat up quite a bit. they can also heat the water up; so are normally suspended at a fair height above the tank.

I personally wouldn't go for lids at all- then again I have no cats.

I've seen some tanks with a partial covering over the tank in the front, but the MH's were directed toward the back./

I suppose you can always try it out, and see what the temps are like. How high were you thinking of suspending it?

you could have a hood to keep the cats out and cut light into the top of it

like livingart said and maybe you could make your hood a bit taller too? just to get the metal halide further away?

Dont waste your time and $

Dont waste your time and $

Why do you say that HaNs ?

$250+ worth of lights + running costs(heaps of heat) when you dont need it

Just run T5's or T8's

$250+ worth of lights + running costs(heaps of heat) when you dont need it

Just run T5's or T8's

I don't think the running costs of a 150w bulb for the duration I will have it on is an issue. The heat I can control as described. The unit I have got has T8's built in so I plan to run it on just those and then have the MH illuminated for a shorter period in the evening for viewing. Plus if I were to invest in T5's it would require extra $$ anyway. Plus I like the effect they have visually :-)

if you think heat might be an issue i could ensure ventilation at the back panel of the lid and/or in the top too - and even put one or two cheap computer fans in the hood for added cooling. what do you think ?

I think you are underestimating the amount of heat It gets HOT!

with computer fans, you can attach a small (240W) PSU to the mains and then comp fans to them, but you will need metal fans as plastic fans will melt.

But that's even more electricity consumption.

If you like the MH effect, and are not going to use it for the reason most others do- that's for corals, plants, and to ensure enough light gets to the bottom of the tank - just get a nice neat looking halogen setup from your local lighting store, and turn them on for a similar effect. its what i would do.

That or t5's But i also have halogens built into my roof.

phoenix44 - what about an earlier suggestion of making a wooden lid and fitting the unit into that ? Im still not convinced that the amount of heat generated from only being on a couple of hours is going to be a problem - and now i have said that Im sure i will be proved wrong but running a couple of fans for that duration is not an issue for me. Really - a couple of fans is going to cost a few cents an hour.

the halides will create a ton of heat if enclosed. I run 2x250W MHs on a pendant approx 30cm from the water surface. Even in winter I have to keep fans running across the surface, and this is an "open air" tank. I've replacing the fans with a chiller this year and a temp controller.

this was my old (v.old) marine tank.

See the hood and how unusually high it is. it had 2 MH's in there. but the rear (and sorry this is the only pic i could find as its from a fair few years ago) was open, and had no wood at the back. there was no glass hood as it would just crack. you can try something like this - but it needs fans. this unit had fans facing the rear, so it pushed air from the surrounding areas and the water onto the MH's and the heat dispersed onto the wall.

Mind you the wall was concrete, and painted and was built around the tank.

the halides will create a ton of heat if enclosed. I run 2x250W MHs on a pendant approx 30cm from the water surface. Even in winter I have to keep fans running across the surface, and this is an "open air" tank. I've replacing the fans with a chiller this year and a temp controller.

Point taken jolliolli - though wouldnt the combined heat of 2 x 250w turned on for a normal lighting duration still generate a lot more heat than 1 x 150w for just 2-3 hours ?

thanks phoenix44 - and an impressive looking tank it was ! Did the hood go any higher than we see in the pic ? I could have mesh or grills in the back and sides of the lid.

Thanks.

Yes, the hood was slightly higher. I think it measured about 15" - 18" in height. the tank was 4 ft long +/- at the back.

the higher the lights are the better the ripple effect too

Heat doesn't need to be a problem, and with only a 150w is easy to get the heat out. I have 2x400w on my tank I have a bathroom extractor fan sucking the air outside. I think you'll find those lighting units have fans at the end(s) to remove the heat so long as you have air flow out the sides or top of your hood it will be fine.

If you get worried about the glass, just buy some toughened glass, it's what they use right in front of the bulbs in the light unit.

Heat doesn't need to be a problem, and with only a 150w is easy to get the heat out. I have 2x400w on my tank I have a bathroom extractor fan sucking the air outside. I think you'll find those lighting units have fans at the end(s) to remove the heat so long as you have air flow out the sides or top of your hood it will be fine.

If you get worried about the glass, just buy some toughened glass, it's what they use right in front of the bulbs in the light unit.

Thanks Suphew - much appreciated input. I will wait till the light unit arrives - its practically new and cost the original owner $995. They used it for 1 week only. Once i have it I can see it and start to plan the lid in more detail.

They get hot enough to give decent burns :oops:

Looks like you have them...was going to make sure you got a modern ballast

Iv got 2 6500k 150w bulbs here that a member was going to buy(he pulled out)