My light question!

[saltjunkie]

Ok,
Heres the deal. I will be setting up my 15g tank soon(same as a 10g just taller).
I will be using my current loa and ahsupply pc setup-100 watts, for the refugium and sump.
I have a 175w mh ready for the main tank. The bulb will be a 10k.
I will have 2 fans in the hood and a 4 inch dsb in the tank.
How high should the light be placed above the tank? This is a small tank, and i know I will have to deal with evaporation, but I do not want to content with heat!
Also, just to get a general idea, I will be utilizing 1 10g lightstrip with a 15 watt actinic in it that will come on before the mh, then shut off after it powers up. It will then come on at night when the mh goes off. Any other suggestion or ideas would be cool and appreciated, as this will be "my" first mh set-up.
TIA.
Rick

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<center>NORMAL PEOPLE WORRY ME</center> rick@reefland.com
visit my micro reef and lowrider page! Saltjunkiesreef
It is always under continuous change

[saltjunkie]

wow guess i better post this in the reef forum to get more responses!!! Haha. Lol
But really thanks ninong for the email!!!!

[ronjon]

i am guessing that your going to have all this set up inside your hood? have you made a hood yet?

wondering,
rj

[lakedawgs]

Just an FYI, I have a 15gallon nano thats not the same footprint as a 10 gallon, its 24" long.
thanks,
lakedawgs

[naser]

wait till summers over.

[saltjunkie]

ronjon,
No, i havent made the hood yet, but it will be basically the same as my current hood...just finished this time. That is why i was wondering about the height of the mh.
To get an idea of how it will be mounted, picture this...
The angled part of a lightstrip will be mounted to the inside front of the hood, making the light angle towards the middle part of the tank. The mh will be mounted as far back as possible on the top of the hoo. this setup keeps the lights from interfering with each other. It has worked great in my hood now, i will just really be replacing the loa 65w with a 175w mh.

[Rin]

Most of the heat you will have to contend with will be radiant heat. Thermal heat will make for just a little bit of the heat added to the tank.

You can feel radiant heat by placing your hand in the hood with the light on. The side of your hand facing the light will be warmer than the side facing away. Turn off the lamp and let it cool just a little. The warmth you feel inside the hood is primarily thermal heat. Not all of it, but most. The objects inside the hood will still give off some radiant heat.

There isn't much you can do to prevent radiant heat from entering your water without also stopping the light. So that leaves 3 main ways to remove heat from your tank. 1) Thermal Radiation, 2) Mechanical Removal, 3) Evaporation.

1) Thermal Radiation--As things heat up, they also radiate. This can occur through the sides of the tank, through the sump, and through the refugium. Some folks put their sumps in cooler areas--like basements.

2) Mechanical Removal--Ice packs, chillers, etc.

3) Evaporation--This is the primary means of removal for most folks. Give yourself plenty of air flow across the top of tank, sump, or refugium. You'll probably want to include a top-off system of some kind to help you along.

How many gallons total will you be dealing with? The more water that is going through the sump and refugium, the less heat rise you will experience. A 175W MH is going to pump a lot of heat into the system.

HTH,

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-Todd
'Only the corrupted can recognize true innocence for what it is.'

[saltjunkie]

I will have the main display tank, 15g, 1 refugium 15g, 1 sump, 15g. These are the main water carring tanks of the system. The stand was made so that a large rubbermade container will sit above my sump and drip/top-off the whole system, this is about a 30g tub. I will have pc lighting over my refugium, but not the sump. Total useable water volume will be around 45g with the continually available supply of fresh, cool water.
Should I put a fan under the cabinet also?

[Rin]

If you want to promote more evaporation in the sump, it might not be a bad idea, but the two fans in the hood should be sufficient.

45 gallons sounds like plenty of water to handle the heat flux from the lighting (MH and NO). Distance from the water isn't very relavent in this case when you're talking about a difference of only a few inches. I would do it the same way you are now, the MH as far up as possible and as far back as necessary to clear the NO light.

As a guess, you'll probably loose a little less than a gallon of water/day with that setup.

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-Todd
'Only the corrupted can recognize true innocence for what it is.'

[saltjunkie]

I got the 15g tall because I already have the 10g micro reef set up and I was just transfering my stand and hood at the time. But now I have redone alot, like my stand and all equipment. I really like the small tank look and price to stock and light etc...

[InsaneCaine]

lakedawgs,

I think saltjunkie is talking about a 15 high which is the same footprint as a 10 gallon. A 15 long is 24" long. There are sooo many different tank measurements with the same gallon size, like a 20 gallon standard is 24" long, but a 20 gallon long is 30" long.

saltjunkie, I was just wondering why you chose a 15 high instead of a 15 long. I'm not saying you should choose one over the other; I am just curious, as I have always heard that longer is better.

[reefland]

Knowing what Rick's stand looks like, I would offer the following suggestions:

Place a custom tank on the lower level (26"x18"xX) of the stand with your 10 gallon refugium on the higher part (which is about 18" higher than the lower level and to the right). Drill the 10 gallon in the back and gravity feed the refugium to the display. Use a smaller matching canopy to hold the PC's over the refuge. Place the 175 in a real tall type canopy (which would actually be as high as the top of the refugium canopy) then with an internal shelf inside you can place the MH where you like. The larger area will allow you to use some inexpensive fans inside. This would make your cabinet an entire unit.

Since you already have the 2 part sump completed, place a DSB in the first section and continue on as planned with the other box. Use 2 Mag 250 returns, one for the refugium which would have slower flow since it had more head and one to the display.