Evaporation, Chillers and Heaters in the Desert

[azreefr]

A few questions about desert aquariums. Can anyone educate me on tank evaporation and water temperature here in Phoenix. My house is 82 degrees when I'm not home in the summer. I'm trying to size my sump so it will handle 2 to 3 days of evaporation for my 30 x 30 cube.

To maintain the temperature do I need to get a chiller or a fan? Or will the flow in the tank lower the temperature? I'm going to be running LEDs and the submersible return pump I'm buying isn't suppose to put off much heat.

Since its so warm in the summer and pretty mild in the winter how many watts per gallon does everyone run?

 

[dotcommer]

I have one aquarium in the basement that I keep the room temperature at 73 to 74 constantly, and I have an open style canopy with two fans. I have two 250 watt MH lights and my temperature will get up to 82 degrees in the tank during the day. I have a submersable pump as my return. Its a 90 Gallon tank. I am going to hook up a chiller, to keep my water temp more constant.

 

[bugs713]

I keep my house at 74 summer, 68 winter and keep my salt tanks at 80 year round.
I have DIY LED on all of them and use no chillers. In your case though, you may need a chiller unless you lower the house temperature a bit. I know some successfully keep salt tanks in the 82 range, but IMO that is too warm especially for some species.

Some submersible pumps can up water temperatures 2+ degrees, I had a Mag that added 4 degrees. Currently use a Eheim 1260 sub in my 55g with little to no heat and external pumps on my 185g.

Fans can and do help when blown across the surface, but only to an extent, depended on the CFM of the fan and the size of the surface area.

I evaporate a good 1.5+ gallons per day in my 185 and .75 in my 55g, but I have good surface agitation to further help with gas exchange.

Look into an ATO set up, then you don't have to overly worry about sump size. ATO's can be done cheaply AND they make fish keeping much easier than lugging heavy water around every few days. They also help with the stability of the tank as it slowly replaces lost water instead of several gallons at once.

Good luck!

 

[azreefr]

I can only imagine what my electric bill would be at 74 degrees during July and August! I guess when I get it set up I will run if form a few days with tap water to check for leaks and see how hot it gets. What temperature do you run your tank at?

 

[jporter]

Here is my 2 cents and what I've noticed firsthand on my tank.
I have some fish that require lower temps so I try to keep my tank as close to 77 degrees as I can.

My original tank set up used some mag pumps and I had my canopy back and top sealed. I run 2X250W MH's with the light fixture fans ducted to the garage.I also used a 1/3HP chiller. Temps stayed between 76.8 and 78.2. The chiller cycled approx. 6 times a day and would stay on anywhere between 30 min and 1.5 hours depending on if the MH's were on. One day at the beginning of summer, the chiller died. Needless to say I freaked out a little.

Here is what I did -
I removed the back and top material from my canopy. Added a little 3" desk fan to blow across the top of the display tank. Reduced MH time to 4 hours and set Apex to shut off MH's if temp went above 80. I have since added a second 4" fan to blow across the tank in the opposite direction. I have the fans controlled by the Apex so they shut off when the temp gets back to 77.

What I noticed was the fans do a better job at keeping my temp steady and I don't have continuous spike with the temp. The warmest the tank gets is 79.4 and it only does this once a day while the MH's are on. The only drawback is I have to add more top off water every day and that is about to be fixed with an ATO. I'm sure I'm saving money as the chiller had to be using lots of power running so many times a day. We do keep the house a little cool at 75 in the summer.

Evaporation cooling Pros:
No chiller
SRP bill less because of no chiller
Better temperature stability - Only one heat rise a day during MH time. Max temp 79.4 and then returns to 77 a couple hous later
Room is quieter with no chiller and more open. Every chiller is an eyesore
I believe there has to be a benefit to topping off more frequently and adding fresh RODI.

Evaporation cooling Cons:
Adding more top off
Adding fans to blow across water
More open canopy - I don't like seeing light from the top, light fixture fan noise

Again, this is my experience and others may have a totally different opinion/experience. I have been running this way for several months now and have noticed ZERO negative effects on the tank or it's inhabitants. I have since upgraded my skimmer and return pumps to DC models. This has further helped with keeping the temp cooler in the tank. Once I get my ATO system going I think I'll like this setup even more.
Hope this helps. JP

 

[azreefr]

Thanks. This helps a lot! My tank is rimless and I plan on keeping the top open with no cover of any kind. Just need to select fish that won't carpet surf. While I'm cycling the tank I will be able to get a chance to monitor the temp and try fan(s). I was going to wait to get an Apex. But after reading posts on controlling power heads, heaters, and now fans for cooling I think I just need to fork out the cash now.

 

[Weyrman]

I keep the house between 81 and 87 in the summer depending on humidity levels. Right now its at 81. I have three six inch fans for cooling which are hooked up to an RKL. It tells one fan to come on at 78.5 and the other two at 79 degrees.

The DT is 150g plus about 20g in the sump. Open top with three Radion LEDs. External return pump. The temp bounces back and forth betwen 78.4 and 78.5 when the house temp is 81. One fan kicks on and off. At 87 all three fans run almost constantly and the temp remains right around 79. Evaporation is between 3 to almost 5 gallons a day. I use an ATO to keep the water level even. Above 87 in the house and the fans start to fall behind at cooling the tank. At 92 degrees in the house the tank hits 82 degrees. I have two spare fans for in case the need arrises.

Winters the house is around 68 degrees. I use two 250 watt heaters controlled by the RKE. One kicks on if temps fall below 79. Both are on if it hits below 78.5.

I looked at chillers but the additional electrical load would be too close to maxing out the circuit when everything is on.

 

[mvergas]

I have been running a chiller for the past two years now. True, there is a higher cost both in equipment and electricity, but I could never see myself without one now.

 

[azreefr]

Thanks weyrman. Never thought about staging the fans. I have a similar situation with my circuit load. No way to add another breaker without doing some major wiring. Where do you have your 3 fans mounted? Could you post a picture?

 

[Weyrman]

Thanks weyrman. Never thought about staging the fans. I have a similar situation with my circuit load. No way to add another breaker without doing some major wiring. Where do you have your 3 fans mounted? Could you post a picture?

They're just clamped to the top edge of the canopy pointed at an angle towards the water. One in each corner. Same on my FRAG tank. This is a phone pic of the one on my frag tank.

They're just $10 6 inch 2 speed fans that come with a base and a clamp. Be sure you use a GFCI.

 

[Henchman24]

Everyone's setup is going to be different. You really need to monitor your tank's temperature throughout the warmest part of the day to see if it gets too warm under your conditions. If you are still setting it up this is a GREAT time to find out what temperature fluctuations you see after the tank is filled before adding livestock. I am using led's & keep my apartment at 74 in the summer. Water temp in the tank ranges from 76 to 78. I have never turned the heat on in what is considered winter in Arizona. In my opinion you can completely ignore the temperature outside. The temperature inside your house "conditioned space" v.s. the temperature you wish to keep your tank at is what is critical. If the house temperature gets to 90 than you need a way to lower the tank temperature. If you have your ac cranked and house stays at 50 then it is not needed. Fans from my understanding can lower the water temp as much as 10 degrees. Using fans with a controller that will turn them on when needed is ideal to me. A chiller is needed if you need to lower the water temperature more than what fans cooling can provide.

 

[zrogst]

How is everyone surviving with their houses at 80??? Our thermostat doesn't go above 76 ever, and I feel like the hotter it gets outside the cooler I want it inside.

 

[Weyrman]

Jeez! Take your sweater off! We have it set to 92 at the beginning of the summer before humidity sets in. Then as the humidity kicks in we gradually lower the temps. We're at 81 now but humidity is lowering so time to begin ratcheting back up. We're from Washington State where 85 is hot because the humidity is so high. This dry heat is great!

Though when it get's to above about 110 degrees that is a bit too much to enjoy the out of doors. Except in the pool of course.

Are you an AZ native?

 

[brian cummings]

my old lady and I constantly fight over the thermostat setting, she usually has it at 81, it drives me nuts. I have a chiller on my tank, otherwise, I probably wouldn't be keeping seahorses...

I'm an AZ native, lived here all my life except for a couple year stint in Japan. I will say that the dry heat is better than humid, it never went past the 90's where I lived in Japan but the humidity made it absolutely miserable. Once I finish grad school I want out of the desert heat!

 

[jesusmeza80]

Holly crap! My ac is set for 73 during the summer! I have to be comfortable in my home! Yes the electric bill isn't very nice to me but. I must be comfy at home. How do you guys do it. I would probably die if my house hit 80. Lol

 

[azreefr]

73! That sounds like winter to me.