# 70 watts Metal Halide over an ADA 60p?



## kkau1 (Jun 22, 2006)

Hi, 

I was wondering, is 70w metal halide too much light for a 60P? I believe the 60p is 18 gallons ish. Anyone have expereince with this? I'd really like to make my first ADA setup look really nice, but don't want to zap it with too much light and end up with a mess.

Thanks~


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## aquanut (Jun 26, 2007)

not even close if your co2 is good, in addition to having good water movement....im in the process of putting a 150watt MH HQI and 2x55W CF over my 60P. It will only be about 80more WAtts than I am currently running, cant see why it would be a big probelm.


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## rwong2k (Jan 13, 2005)

70/18 ~ 3.88 wpg, not too familar with the dimensions of this tank.

But yeah co2's important.

What type of plants do you plan to keep in this tank?

i have 150 over a 20, and I only have my photoperiod for 5.5 hours per day, I started with 4

Raymond


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## hoppycalif (Apr 7, 2005)

You can use as much light as you want on any tank, but if you want to use that much light you really need to use pressurized CO2, and keep the amount in the water the same every single day, with very good circulation of water all over the tank. Plus, you need to be very attentive to fertilizing well and providing all of the needed nutrients. Then, you need to limit the time the lights are on well below 10 hours day. Do all of that and you have a chance to avoid algae problems.

Or, you can just use 2 to 2.5 watts per gallon, with good reflectors, and not be so anal about keeping everything perfect.


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## kkau1 (Jun 22, 2006)

Yep, i'll be running CO2 etc... EI dosing. I was just wondering if 70W Metal Halide over 18 gallons was a lot more light than normal. I've never done metal halides before. Also, heard that since metal halides are continuously on, while T5HO's etc... flicker really fast, if that made a difference, since 70W over 18 gallons only equals 3.8 ish watts, which doesn't sound like too much.


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## Rastaman (Jul 24, 2006)

What about distance within lamp and the surface of the water? I think it's absurdly to talk about wpg without that, and "minimum light threshold" phenomen was still there to mess up your calculation. 
Check this article for adjusting right distance depending on plant metabolisam.
I have 70W MH over 4 gallon, 40cm above surface. Vide


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## kkau1 (Jun 22, 2006)

I guess my final question is this:

is 70w MH more light than 100watts-ish T5HO?


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## aquanut (Jun 26, 2007)

its really hard to say.

its depends on what kind of ballast and bulb you are using. in any case, it certainly wont be TOO MUCH.


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## hoppycalif (Apr 7, 2005)

It also depends on how high you suspend it above the water. If you have a lot of light spillover, that wastes part of the watts (light). And the T5 fixture would be more efficient with good, individual reflectors for each bulb, than with a single, not so good bulb.


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