Cooling

So I've been looking to cool my 120 gal. tank and I don't want to buy an expensive cooler for it.  So I thought I would make my own cooling unit.  I already have 4 fans blowing on all my water and sump and it still doesn't cool it enough.  So here is my thought:

I will use a small pump to pump water out of my sump into either a radiator or transmission cooling system.  Then I would have 1 or 2 fans blowing on the cooling system.  As the water passes through the cooling system it would cool down the water and then release it back into my sump.

Does anyone see a problem with this?  I'd like your opinions.  Especially Mark Peterson who is the master of DYI

Tell us about your setup...what kind of lights do you have, how close are they to the water, and do you have your pump submerged? All these things can affect the heat in your tank. Also what size of tank is this and how much evaporation do you get a day? You should be able to cool the tank with just fans...I have over 1000W of lights on a 90 gal and I am able to keep it at 78.

WELCOME HereFishyFishy.

What size are the fans? I have two 250 watt MH on my 120 gallon and keep it cool with one 7" fan. I think we can help you do this without too much trouble or expense.

Mike

Hey I have been thinking about this issue for my system as well and I choke when I see the cost of chillers. I am in the HVAC business and have been for some time and it just looks crazy to me to see these itsy bitsy cooling systems cost as much as the equipment for an entire house.

So with appologies to Mike (because I really do agree with the keep it simple approach) here is what I am considering . . .

I have a small refrigerator that I no longer use. The compressor on it is rated at around 1/5 HP as I recall, which as far as energy used equates to a decent size commercial tank chiller. (I need to verify this and the BTUH rating for better comparison)

I was planning to coil as much PEX piping (1/2" dia) as I could inside the cooling compartment and possibly place it inside a bucket full of water to act as a better thermal mass. After drilling two holes in the side of the refrigerator I would extend the piping to my sump and place an inline pump at the head of the piping.

Control could be a simple aquastat that would close a contact relay to start the pump on a call for cooling. The flow will want to be fairly low to permit the release of heat in the refrigerator compartment and to minimze the stratification in the sump. I realize the unit may not be able to keep up with the demand at all times but due to the mass of the tank and the potential in the mass at the cooler it has a good chance of working. 

I will be doing some more research on this in the coming months and will happily share my findings for any interested.

I know it's kind of a an unsystematic approach and I may be a bit irresponsible for mentioning it without more research but, there I've said it.

YMMV

Rod

Fishy,

Yes 84 is too warm especially this time of year as it will probably increase when the weather heats up.

My lights are also 10" from the water to the bulb and my pump is in the sump so it adds heat too. Aluminum also corodes in salt water.

Something sounds fishy here.

If the tank is in the basement and it still rises 10 degrees something is not behavein as it should or you have it set up different. Can you describe how the lights and fans are situated.

It sounds very familiar. Did you post about this under another name a while back when you were building the hood and putting in the fans?

There are many variable that could cause this tank to be warmer than someone elses tank that runs more and hotter lighting.  I'm afraid I may soon be dealing with the same problem.  I now have 4 tanks in the room I call my office in the basement.  The lighting puts off enough heat that in the afternoon I have to open the window to let cool air in even in the winter.  (and to think I used to freeze while trying to work in here in the winter.)  I'm not sure what the answer is, but I'm sure I'll be looking for them soon myself.

Here is an interesting question I've been worried about as things warm up that also has some tie to this thread:  For those of us that cool our homes with Evaporaive Swamp Coolers  has anyone noticed that they have enough humidity in their house from tank evaporation that the Swamp Cooler doesn't seem to cool like you might think it should?

I forgot to mention that I run two blue 4' VHO's as well.  This is how I setup my tank:

I run 2 fans 24/7.  About 11a.m. my two blue VHO's kick on.  Around 12 noon my 2 MH kick on along with my 2 other fans.  Around 10p.m. my MH turn off along with the 2 extra fans.  About 11p.m. my 2 blue VHO's turn off.  So my photo period is approximately 12 hours.

The comment from Gahlenfr is making me think.  I might be pushing hot air around.  I have one fan 24/7 blowing on my sump (no cold air coming in).  I have all other 3 fans blowing down from the top of my hood.  Yes, I have an open hood so all my fans blow down onto the water.  However, the top of my hood is only about 6" from dropped ceiling.  So I don't have a lot of clearance.  Could that be my problem?

So here is what I've done.  I've taken the fan off of the sump.  I've put one fan at the top of my hood (on the far left) blowing the hot air away.  I've also put 2 fan, one on each side, blowing directly down on my water surface.  So far it looks like my night time gets down to 74deg. and during the day with my lights on I'm getting to 80 deg.  Is this acceptible or do I need to keep the tank cooler?  Are there benefits to having cooler water?

That's much, much better. Are you willing to work on it a little more to get it down to 78 max? If so, please fill in some missing info.

Are the fans running 24/7 or just when the MH's are one?

Are the two fans taking air from outside the canopy?

Can you give us a measure of the angle at which the air from the fans is hitting the water? and how much are they angled in to the canopy area?

What is the actual room temperature?

And last, would you be willing to reduce the MH Photoperiod by 2-4 hours?

Sorry for all the questions, but this info really does make a difference.

Edited by Mark Peterson