Temperature issue? & UV sterilizer

[aquiman]

Hello all. I have a 90g FOLR tank that's up and running about 2 months now with about 7 fish and all is well. I have sump and refugium and protein skimmer and the tank is running around 80 degrees steady without the heaters even kicking in. I think the heat is coming from the main & PS pumps. Do I need to be concerned about bringing the temp down a few degrees? Also, even though controversial on the forum, I am planning on adding a UV sterilizer for proactive disease purposes. Can I expect my heat issue to get much worse with the UVS? Suggestions welcome. Thanks!

 

[saxman]

It depends on how powerful your UV unit is, and what your contact time is (how fast the water flows thru the UV unit), however, the short answer is yes, it will add to your system temp, how much is the question.
Certain pumps run hotter than others, to be sure. If you're running external pumps, you can cool them off a bit by directing a fan over the motor casing. If all your pumps are submersible, you can swap them out for more efficient pumps, add a chiller to the system, or try blowing a fan across the water in your sump.
Since your tank runs so warm, you may want to unplug/remove the heater if you have one.
Which pumps are you using?

 

[aquiman]

Hi and thx for the quick response. Both pumps are submersed in sump. The main is a Supreme by Danner model 9.5 (950 gph). The Aqua C Urchin skimmer pump is a Rio 1400 (420 gph). The UVS I'm looking at is Coralife 6x 18watt unit. Prices on chillers are crazy so hopefully it won't come to that. Heaters have been turned down but I will unplug to be sure. I have left the stand Door open which helps but not enough. A fan sounds good. Any idea how much worse the UVS will make the situation? With the water currently running between 80 and 81 degrees, maybe the UVS is a bad idea for the heat reason? Thanks

 

[saxman]

Mag 7's and larger tend to transfer a fair amount of heat into the water (esp. in submersed applications), but other than that, are good solid pumps, and I have a few that are ancient and still work well. A Mag 9.5 dissipates 93W/hr, so *if* you wanted to re-pump the tank, you could improve that some.
As for HOW MUCH a 18W UV unit will heat your water, it really depends on contact time, which equates to how much flow is running thru it. The slower the water runs, the more time the UV unit has to heat the water, however, you need to match the flow to the largest organism you're targeting or there's no reason to run it at all.
Things you can do that are pretty easy:
Run a fan across the surface of the sump and/or DT. You can get inexpensive 120V clip-on fans or even DIY some computer fans or muffin fans for this application.
Reduce your photoperiod or the number of lamps you turn on. Also, run your lighting in the evening when you're home and viewing the tank...it's cooler in the evening.
If you have a tight-fitting lid on your tank, slide it over a bit so warm air between the lid and water can escape. Likewise, you can aerate your water a bit more which will also cool it (also an evaporative cooling method like the fans).
Be sure to keep up with your top-ups, as evaporative cooling will increase your need for FW.
HTH

 

[aquiman]

Thx saxman. A few questions a comment or two on your response. Can you tell me what you mean by repump the tank? As for the UV and targeting, I don't know at this point I'd be targeting anything in particular. I was just thinking about it helping with disease prevention and to help a bit on algae. Am I missing something? I like the idea on a fan in the stand running over the sump. I addition to that, I think I'll cut in some vents into the stand sides. As for the top, mine is all glass (2 pieces - 1 on each side) with the back two inches plastic. What if I were to drill a bunch of small holes in the plastic to let the tank breath? I will also adjust my lighting pattern to help as well. What do you mean by evaporative cooling? Thanks again.

 

[geridoc]

Quote:
Originally Posted by Aquiman http:///t/392984/temperature-issue-uv-sterilizer#post_3493282
Thx saxman. A few questions a comment or two on your response. Can you tell me what you mean by repump the tank? As for the UV and targeting, I don't know at this point I'd be targeting anything in particular. I was just thinking about it helping with disease prevention and to help a bit on algae. Am I missing something? I like the idea on a fan in the stand running over the sump. I addition to that, I think I'll cut in some vents into the stand sides. As for the top, mine is all glass (2 pieces - 1 on each side) with the back two inches plastic. What if I were to drill a bunch of small holes in the plastic to let the tank breath? I will also adjust my lighting pattern to help as well. What do you mean by evaporative cooling? Thanks again.
Heat of vaporization is the heat required to convert a liquid to a gas at its boiling point. For water this value is about 2200 kilojoules/kilogram. What this means in English is that when water evaporates (goes from liquid to vapor) even when it is not at its boiling point, it consumes some energy, that is, heat. This has the effect of cooling the remaining liquid (in this case, your tank). This can be a pretty effective mechanism for limiting the heat rise in an aquarium. When I had my 110 gallon system running it would stay at 75-79 in the summer even if the room was considerably above that, but I had inline rather than submerged pumps. All I used to control heat rise were two small computer fans blowing across the surface of the wet/dry sump. Evaporation was pretty high, and I was constantly carrying RODI from the basement to replace evaporative losses. I now have a 220 gallon tank, and have all the pumps submerged in the sump in order to control noise. That works, but the heat from those pumps has nowhere to go other than into the water, and the tank temp gets far too high for the organisms. So now I get to use a chiller

. I'm about to add an algae scrubber to the system, and intend to bulkhead the sump and use an inline pump for that in order not to add more heat to the water.

 

[aquiman]

Thanks again for the info! Hopefully it won't come down to a chiller. I'll try the fan, venting the stand and drilling some small holes in the the top plastic edges first and hope for the best.:laughing: