DIY Chiller

[Piscesgirl]

Alright, Thanks Wright!

[whuntley]

We do drift OT here, don't we?

Getting back to chilled tanks, the killietalk list has had a good thread, recently, on cool-water fishes. Since SG has the opposite conditions, I suggest it is an interesting read.

I went back to ebay, this PM and was floored by the bargain Peltier (thermoelectric) coolers for sale. In anticipation of our hot summers, I am still thinking of a good, general-purpose system that should be way cheaper, and far, far more compact, than the freezer/bar refrigerator design.

[Am I nuts? It is -6C outside right now! When I got back from Reno, yesterday, I had no water. My pipes were frozen! Water from the toilet, boiled and then poured over them, fixed it, OK. I forgot and left two outside faucets open, so had to wade to turn them off. My toes are still cold!]

Any way, the problem of condensation rears its ugly head in humid places like SG if you ever get a tank cool enough for Diapterons. Has anyone considered various schemes for keeping mirrors clear in the bathroom, etc., for keeping visibility acceptable on chilled tanks. Clear plastic film, like Saran, must work to keep the cold glass from becoming obscure. No? How to mount it?

How about wetting-agent sprays to cause the condensation to not bead up?

I'll be getting some processor chillers and TE plates, soon, and mating them to black anodized plates to go down inside the back of the tank. They will work great here, but I feel we must make the tanks aesthetically acceptable in SG if the solution is to be universal. Suggestions?

Wright

PS. I bought a nice bunch of 50W heaters and will cut my house-heating bills as soon as they are installed.

[FC]

Wright,

Do you think you a coat of "Rain-X" (a form of silicon) would help?

[whuntley]

I don't know, Freddy.

My ability to create a fogged tank is pretty limited, summer or winter, so the solutions may need to be found and tested in SG. No?

Be very cautious with sprays, as they may be lethal if any gets into the water.

One I would try, if I had condensation problems would be a frame/gasket made of 1/4" clear acrylic square rod, with Saran or other clear food wrap stretched smooth on it. If you can't install it totally dry, a small packet of dessicant between the glass and plastic might be needed.

Wright

[keehoe]

Aluminium is poisonous but Aluminium Oxide is not. Al is highly unstable that would ever ready to oxidise. You can only get the poison by scraching off the thick Al oxide. But again within fraction of second the surface turn into Al oxide again. Al is good electricity conductor Al Oxide is not. Ever try to use carbon to di oxidise Al Oxide? How much energy is required to make that possible? I think naturally, it won't happen.

[whuntley]

While studying thermoelectric alternatives, I came across this site:

http://cgi.ebay.com/ws/eBayISAPI.dll...349529953&rd=1

Since it is an asian product, it might be reasonable to order in your part of the world.

The big advantage of thermoelectric units is the ability to either warm or chill, and this one seems to have that feature. The circuit may be simple, but the design is more tricky than it appears to be.

Do note that the degrees are probably F and not C.

Wright

[timebomb]

I replaced the hose inside the freezer just before I left for KL 2 weeks ago. Now, it's just a 12 metre hose, much shorter than the 50 metre one I started with. As far as I can tell, the temperature of my fish tank remains about the same, at between 23 to 24 C. The temperature of the freezer though has gone much lower. Now it hovers at about 17 C most times.

So I think I was right about the length of the hose having little effect on the efficiency of the system. I wonder how short I can go though. If I cut the hose to only say, one metre, would the results be the same?

A short hose would mean the water that flows from the fish tank stays inside the freezer for only a short spell. But it would stay in much colder water so the overall results remain the same. A short hose also improves the flow-rate.

Loh K L

[TyroneGenade]

You had 50m of hose to begin with correct ? You have tried 37 and 12m... now try 25 and see what happens... That your freezer is cool suggests that the system is performing slightly more efficiently. You should be able to find a hose length where both the freezer and tank are cooled at an optimum.

tt4n

[timebomb]

You had 50m of hose to begin with correct ? You have tried 37 and 12m... now try 25 and see what happens...

Well, I don't know if I really want to try that, Tyrone. My guess is if I use a 25 metre hose, the temperature in the freezer will rise to between 19 to 20 C. My fish tank temperature should remain at about the same as it is now, between 23 to 24 C.

I'm skeptical that there's an optimum length. I have already tried different lengths, 50, then 38 and now 12. The temperature of my fish tank was the lowest at about 22 to 23 C when the hose was at 38 metres long but I suspect it was because it coincided with the cold spell we were having in Singapore. Now, ambient temperature has gone back to about 30 C and with a 12 metre hose, I'm getting 23 to 24 C in my fish tank.

One mistake I made when recording the temperatures of my tank and freezer when the hose was 50 metres long was that I didn't take note of room temperature. It's an important factor and I should have realised that earlier.

I'm glad I decided to take up your earlier suggestion to shorten the hose though. A shorter hose makes for a much improved flow rate. If I should change the length of the hose again, I'll probably try one metre.

Loh K L

[TyroneGenade]

Hello,

I here it is warm again. What is the temp of your tank currently? Has it changed very much if at all?

tt

[timebomb]

Tyrone,

Yes, it's been real hot recently. Room temperature now is about 32 C. I don't know what it is like outdoors but it's scorching.

I made some changes to the DIY chiller recently. A couple of weeks ago, for no apparent reason, a few of my Otos in the tank died. The water was also always misty. My wife kept complaining that there must be something wrong with the system. I checked with a friend and he said that the braided hose I'm using could be the cause. He said I should use an Eheim hose which, according to him, does not contain phenol. I googled for Phenol and here is what is said on one website:

HIGHLIGHTS: Phenol is a manufactured substance found in a number of consumer products. Skin exposure to high levels of phenol has resulted in liver damage, diarrhea, dark urine, and hemolytic anemia. Phenol has been found in at least 481 of the 1,467 National Priorities List sites identified by the Environmental Protection Agency (EPA).

So I decided to change the hose into an Eheim one.

The hose is 10 metres long and I also changed the settings in my timer such that the freezer now runs for only 16 hours a day. During the first few days when the weather was cooler, the temp in my tank was about 24 to 25 C. Now, it hovers around 26 C. The water is no longer misty and no fish died. I suppose the braided hose I was using earlier may have contain phenol but I don't really know for sure. I'm quite sure I can lower the temperature further if I let the freezer run for longer hours but considering how hot it is outside, I'm quite content with 26 C.

Loh K L

[skhastagir]

dear all
how is the chiller working now? i am planning to build a similar chiller but i may use aluminium tubing .please advice.
thanks
sugato

[timebomb]

Dear Sugato,

The DIY chiller is still working fine.

I suppose with an aluminium tubing, you should see better results. But the most important factors are the size of the tank you want to chill and the chilling capacity of the freezer itself.

When I started, I wanted my tank to be as cold as possible. But on hindsight, I would say that isn't a good idea because when the tank becomes too cold, there's condensation. It's fun to see condensation on the sides of the tank once in a while but it's a big bother when it happens too often.

So whatever you do, you should take into consideration your room temperature. Too great a difference between the temperature of your tank and your room will result in condensation.

Loh K L

[skhastagir]

dear Loh KL
thanks for your reply. yes you are right.i would like to avoid condensation.can you tell me what sort of temp diff causes condensation?
for example my room temp in summers is around 29 C, so till what temp can i go down without condensation?
in your opinion what is the ideal range of temp to maintain in planted tank?
thanks
sugato

[skhastagir]

dear Loh KL
also i know copper tubes are not good for the tank inhabitants. can you confirm that aluminium tubes coming in contact with tank water can cause any harm?
is there any definite source to confirm that?
thanks
sugato

[timebomb]

is there any definite source to confirm that?

Sugato,

I don't think aluminium will cause any harm but Tyrone who's a chemistry teacher said this:

1) do not use Aluminium. It will upset your plants as any dissolved Aluminium will compete with calcium in the plants (and fish) and stuff its physiology.

I wouldn't want to argue with Tyrone over this as he probably knows a lot more about metals than me but I would think that even if aluminium dissolves in water, the amount would be so little it wouldn't do any harm.

If I were you, I would just go ahead with the aluminium tubing. You'll never know until you try.

Loh K L

[timebomb]

can you tell me what sort of temp diff causes condensation?
for example my room temp in summers is around 29 C, so till what temp can i go down without condensation?
in your opinion what is the ideal range of temp to maintain in planted tank?

Sugato,

If your room temperature is 29 C, I would say you should aim for 24 C in your tank. With mine, condensation does not occur when the tank is 25 C and above. My room temperature is about 30 C mostly, 33 C occasionally.

I'm not sure what's the ideal range but I know most plants will do okay at temperatures of 28 C. Some are okay even with temperatures as high as 33 C. Only mosses, ferns and certain species of Aponogetons require low temperatures to grow well.

By the way, where do you live, Sugato? Are you from Indonesia?

Loh K L

[skhastagir]

dear loh k l
you have a pm.
thanks
sugato

[timebomb]

Dear Sugato,

I checked but I couldn't find any private message from you. Are you sure you send it correctly? In any case, there is no need to inform me of a private message. If there's one, I will know. We want this forum to be a place where users treat each other with respect and consideration. To post a message that is of interest to only one person is disrespectful of others because you'll be wasting their time when they click on your post. Please do not do it again. Thank you.

Loh K L

[skhastagir]

dear loh K L
point well taken.i will keep that in mind.as regard to your question i am not from indonasia but from india.
will keep the forum updated about my chiller developments.right now busy in procuring the parts.
thanks
suagto