Evaporation In Tanks

:OT: i dont know about the evaporation, i i recently heard morgunda say that he has heard that if one fan is blowing out, that fan will be more susceptible towear from the salt in the air.

I used eggcrate on the top of the canopy and have both fans pulling air in the heat rises up and out. My 2 cents

One gallon a day is not so bad- I generally end up adding about two.

Yeah, one gallon per day isn't bad at all. I go through closer to two gallons a day on my 100g with MH lights. I also agree that having a fan pulling moist salty air out of the canopy will shorten its lifespan. I use two fans, both pulling fresh air inward - works like a charm.

Ok, let's say that I put both of my fans blowing inward, and I have an enclosed canopy, should I make holes ro something for the hot air to escape?

Anthony8858 said:

Ok, let's say that I put both of my fans blowing inward, and I have an enclosed canopy, should I make holes ro something for the hot air to escape?

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The easier it is for air to escape, the more efficient the cooling will be. Is it possible to raise the canopy a little to allow air to pass underneath?

evaporation

I have a 3 sided 120 gallon tank with 2 metal halides and two blues. I had evaporation of over a gallon a day and a water temperature of 82 - 84 degrees even with 2 fans blowing air into the side with two holes on the opposite end in the top of the canopy to allow the air out. I bought a 1/5 hp JBJ Arctica chiller ($559.00), installed it under my house and ran soft plumbing through the wall and under the house. There's no noise from the chiller and the water temp is a constant 76-78 degrees all the time. My evaporation rate has gone from about 1 1/2 gallons a day to about 1/2 gallon a day. I highly recommend a chiller. Not only does it allow for more oxygen in the water (at 76 degrees there is much more oxygen in the water as opposed to 82 degrees), the evap. rate is cut by 2/3's and there is no stress on my corals or inverts and with more fish, the oxygen level in the tank will never be critical. Hope you get it worked out.

Mike

In regards to circulation of air in the canopy... if cooling is an issue than you will have to actually put a little thought into how the fans are set up. You will actually lose cooling if you for example take the top off the canopy and dont adjust the fans accordingly. The idea situation for the cooling will be having the biggest fastest moving current of cool air which will absorb heat and push out (quickly) the hot air. Because of the fact that you need to have decent air flow you dont want to just take off part of the canopy as that could very easily ruin the currents you have running through the canopy. Ideally you would want fans blowing in with a nice efficient (and direct) way for that air to blow over the heat producing things in the canopy (ballast? bulbs? etc) and then quickly leave the hood (best with a fan blowing out). Look at where your heat making parts are in the hood and think of the best way to get the cold air there and quickly out of the hood. If you have good airflow and it gets to all of the things producing heat then you will be good. This will however cause more evaporation (how much depends on how much airflow and where it goes through the canopy) so keep that in mind. If you are planning on putting effort into cooling the hood then you will pretty much have no choice but deal with evaporation. Also look at evaporation as a small way to lower the water temp a little bit. Not much but it helps (just think about when you are wet and then stand in a breeze, you feel very cool but the water/sweat dries pretty quick. Sorry for the lecture and the long post, I am a bit "long winded" today. Any questions or anything let me know, I spend the past 10 years working on the best ways to cool computers and alot of the ideas and principles are usefull here.

Rick