Anyone have experience with chillers?

Hey all. I just purchased a 1/4 hp chiller at a very reasonable price on craigslist to use on my 75gal "Ultimate Native Fishtank." I've been dying for one of these for a long time, since I am limited in my species selection by my tank being at a typical temperature in the 76-78 range. Anyway, the chiller is rather old, has no directions (so I don't know what a good flow rate would be), and actually appears to be very similar, if not the same model as the chiller on the feeder fish tank at Petco where I work. Anyway, I have this monster and am very excited, except I don't know how to hook it up.

I have a HOT Magnum as well as a Fluval 405 on the tank. My current thinking is that I will cut into the return line from the fluval, run it through the chiller, and then back into the tank. However, upon doing some research, I've read mixed reviews on doing this (drsfostersmith.com says it is no problem, and they seem pretty trustworthy though). Seems like it would be much more simple if I had a sump, but I don't. I do, however, have a Rio 1700 the guy threw in with the chiller, which pushes about 700gph (minus head pressure). I can't exactly put this pump in the tank, but if anyone has any feedback regarding whether I can just use my Fluval for flow, or some way to hook up the Rio without a sump, I'd really appreciate it.

The only issue with using the Fluval is a potential reduction in flow rate. Typically that isn't as big a deal as some would have you believe as far as filter performance goes, and the effect may be small in any case. That depends entirely on the flow resistance of the chiller, which is much more readily determined by hooking it up to see than discussing it here.

If you don't get a reasonable flow rate, which mostly means that the temperature difference is too large between outlet and tank, then I really don't see why you can't put the Rio in the tank and just run its output through the chiller. You may need to do something to screen the intake if you have small fish, but it should be doable. You can always throttle the output with a valve if you need to reduce the flowrate.

Very cool, I appreciate the input. I'm not too concerned about a lower flow rate through the fluval so long as it is high enough for the chiller. I have the HOT magnum as well as a Penguin 200 running along with the fluval, so it is quite heavily filtered. Can't wait to keep more montane species/keep everyone in better color. I'd like to see the blue come back in my rainbow darters.

The only parameter that really matters in setting chiller flowrate is outlet temperature. As long as it's in the mid-40s or higher it won't cause any mechanical problems. You probably want it higher than that in any case. Extremely low flows may result in excessive thermal gradients near the outlet, which wouldn't be good for the fish, but again I'd be very surprised if that were actually an issue in practice.

What I would do is go to the drugstore and invest $2 in a thermometer and set the thing up to see how cold it gets. Does it have a thermostat or any other sort of capacity control setting such as a throttle valve in the refrigerant piping? If not then it will be an interesting project. If your living arrangement permits, I would be tempted to do the initial experiment by recirculating water in a bathtub, so as to avoid random changes in the tank.

This particular unit has a thermostat dial that cuts the unit on and off. I'm also hoping that the unit doesn't kick on too frequently since I am hoping to do a 15 degree pulldown. I probably should find a way to test this thing out in a bathtub. I'm not too concerned about a cold gradient near the return outlet though with all the circulation I have in the tank.

I have been wanting to do a chiller for years. I look forward to seeing your results. I have a 405 also and would likely hook it up to the return on it.

I've worked on a couple tanks with chillers. My experiences were not overwhelmingly positive. A few thoughts:

The chiller itself is like a refrigerator - it will chill the water, but the unit itself puts off a lot of heat. You'll want to make sure the chiller has decent airflow, and you definitely don't want it in an enclosed space (for example the closet behind a built in tank). You'll also see your AC bills rise in the summer, because in essence you are running a heater indoors.

Chillers use large quantities of electricity.

When the temperature difference is great between the air temperature and water temperature, you may see condensation on the tank.


Negative experiences aside, good luck! 1/4 hp sounds very reasonable for a 75 gallon tank.

If I wanted a chiller and owned a house instead of rented, I would just tap into my cold water line using a Watts ice-maker installation kit. It costs less than $50 for the whole setup and would also eliminate the need for water changes. Here's a link: http://www.aquaticpl...nge-system.html
I've done some quick math on it and decided that chlorine would evaporate faster than it could accumulate in the tank.

I also need a new chiller and I am not sure which specs this chiller should have. Until now I always used chiller rentals but I will check which specs these chillers had and then hopefully I will find a cheap offer. Hopefully I will find one soon and until then I will use chiller rentals because this is very convenient and besides this it is cheap.

If I wanted a chiller and owned a house instead of rented, I would just tap into my cold water line using a Watts ice-maker installation kit. It costs less than $50 for the whole setup and would also eliminate the need for water changes. Here's a link: http://www.aquaticpl...nge-system.html
I've done some quick math on it and decided that chlorine would evaporate faster than it could accumulate in the tank.

A couple thoughts:

1) If your water system ever uses chloramine (some do on a seasonal basis), then it won't degass like regular chlorine
2) Welcome to the South. The cold water line won't necessarily always be very cold, especially in summer, and especially if you have a house where the cold water line runs through a crawlspace or has a similarly exposed line. Our cold water in southeast VA never gets very cold in summer, and is actually very, very hot in summer until the line is purged (I'm talking over 100 degrees F).

Just wanted to post an update in case anyone was interested.

After a few trips to Lowe's including a debacle involving wrong sized tubing, then watching a sales associate pace up and down the aisle for about half an hour trying to invent a series of fittings that would do what I needed (connect different size tubings from fluval into chiller "in-line" and then chiller "out-line" back into the fluval tank return line) I finally got the unit hooked up. The unit is rather old, having a manufacture date of 1997, so I had to solve an issue regarding the cooling fan that vibrated badly, resulting in a godawful noise. Vinyl tubing was the answer, once cut into small plugs and wedged between the fan motor and the compressor to absorb some of the shock.

The chiller has been quite effectively maintaining a 15 degree pulldown, keeping the tank at close to 60 degrees. However, after running about a month, I noticed the machine's fan was going nearly constantly, despite adequate ventilation, and that I was hearing a "click" every 30 seconds or so accompanied by my lights flickering. Then I stuck my hand in the tank and felt my water than had risen back up to 78. I got very frustrated and figured I had just bought a lemon. I did some research online and figured out that it was the solenoid or starter trying to engage the coolant pump. The fan was running and the compressor was getting hot but the coolant was not flowing into the water chamber. I unplugged the unit for about 2 weeks and about gave up.

Then, while changing my canister filter, with the flow stopped, I plugged it back in hoping for a miracle. It kicked off after running about 2 minutes, having cooled the water in the cooling tower. Back in action! Since then it has been working well, but sometimes still takes up to half an hour of the clicking/lights flickering phase before the coolant pump will engage. If anyone has any experience with refrigeration equipment, is this something that is fixable somehow, or is the unit simply on the verge of breaking down at the end of its lifespan?

I suppose most are wondering about how the fish like it too. They seem to love it! Not much in the way of color change, but they all seem very happy about the cool water, and my redlip shiner females are ripe with eggs, while the male has tubercles and turned orange every time I throw food in the tank. I put a plate of gravel in the main part of the flow in the tank but haven't seen any sign of spawning yet. I will probably set up a dedicated tank to try to breed the redlips, but in the meantime my fish are more comfortable and I know I can winterize them.

Are the internals accessible enough that you can see the pump? It's almost certainly an induction motor, so the only reason I can think of for the behavior you're describing is some mechanical binding in the impeller. The motor is strong enough to overcome it once running, but the static friction was too strong to actually start.

Without disassembling it, I can't think of any good solution off the top of my head.