Bill, there's an even more sobering article on the US FDA's website on the presence of these toxic plasticizers in healthcare applications. Can't recall the link but its there alright. Tells you about every healthcare product that has these plasticizers in their materials.
Fish.. Simply Irresistable
Back to Killies... slowly.
So sayeth the big guys over here: ours in the states are milky white, stiffKL, if its possible, try to get food-grade PVC tubing. These are non-toxic and safe for aquarium applications I think.
(from lack of plasticizers) but can be bent to your will if first placed in boiling water. Costs more, too :wink:
Jian Yang, thanks, I'll check on it in the morning. It'd keep me up all night!Bill, there's an even more sobering article on the US FDA's website on the presence of these toxic plasticizers in healthcare applications. Can't recall the link but its there alright. Tells you about every healthcare product that has these plasticizers in their materials.
Thanks for the info, Jianyang. But I have to confess I'm confused with all these plastics called PU, PE etc.
After all, I'm supposed to be the guinea pig, right? If my fish die, I'll let you all know immediately but I have no intention of throwing away a perfectly brand new reel of hose I just bought. It didn't kill James' Guppies when he was using it but it could be it takes time for the poison to spread. I don't know but I be happy to use food grade plastics if I know where I can get them. Buying from Canada is out of the question as I need it now.
Loh K L
KL, I know about the confusing bit. I was just as confused as you are when I was studying it and I'm still confused even now. I have to admit my knowledge of polymers has deteriorated since I enlisted for NS.
Anyway, I think the shop where you bought the hose from should know which plastics are food grade and suitable for aquarium use.
Fish.. Simply Irresistable
Back to Killies... slowly.
Well, I certainly hope so, Jianyang.Originally Posted by stormhawk
Folks, I have good and bad news. First, the good - the DIY chiller/freezer is up and running. Many thanks to Melvyn Seah and Deric Ong, my 2 close buddies. They did all the work. I took the photographs. Here's a pic:
As you can see, Melvyn and Deric did a pretty good job with the cover and the hoses. The DIY chiller looks neat although my balcony is in a mess. I made some changes to the original plan. Instead of using one external cannister filter, I'm using 2. One to pump the water into the freezer and the other to pump it back into the tank. We tried using one filter but it wasn't strong enough to pump water through 50 metres of PVC hosing. I didn't put in a powerhead and neither did I use an airstone to circulate the water in the chiller. There's a chance the water inside the chiller may freeze but I will be monitoring closely over the next few days.
Here's a pic of the tank inside the chiller with the 50 metre hose:
The hose later started to kink when we fillled it with water. So we decided to loop it lying down instead. Here's a pic of how it is rigged up under the cover:
Okay, that's the good news. Now for the bad.
After the chiller was switched on, I put in a new digital thermometer into my fish tank. The old one went kaput several months ago but I didn't replace it until this evening. The thermometer registered a shockingly low temperature of 26.6 degrees Centigrade.
But it was raining this afternoon so that's perfectly understandable. The 3 cooling fans I was using are pretty effective, I must say. It just makes me wonder if the DIY chiller is worth all the trouble. Anyway, at or about 5 pm, after the chiller was switched on and the fans switched off, the thermometer registered 26.6 C. One hour later, it went up to 27.6 C. Shucks, maybe I should stick with the fans instead
But it's too early to tell, I suppose. Maybe I'll wake up tomorrow morning to find the tank has turned into a block of ice
Loh K L
Hi KL,
I believe that one hour is not enough to bring the water temperature down and I think you have not set the freezer to the coolest setting yet. I am quite confident that this DIY chiller should work.
I am game to build one but that will be later part of the year after I have completed my fish rack and some of my major jobs' project.
Regards,
Ong Poh San
Sounding like a crank, again, but this is not something I would expect them to know. Using such tubing for very short runs, and for filling and drains, doesn't provide the exposure you are causing here, so they have no good reference points or experience to give you good advice.Well, I certainly hope so, Jianyang.
Someone also pointed out that I should have commented on the poor thermal properties of your hose. [Mea culpa!]
It is awful, and I'm surprised you added a second pump to the system. With PVC, you need very, very slow flow if you want much chilling effect, I suspect. Using one pump and throttling it down might increase efficiency a little bit. Rapid flow and two cannisters is probably adding almost as much heat as the system can pump out. What is the Watt rating of the freezer and the two cannisters? The former must be several times the sum of the latter two, to have much "impact." :-) This ignores other heat sources like lamps and other devices.
It sure is fun to kibbitz all the way from CA. That's a mighty big ocean to come across and kick my backside for being a troublemaker. :-)
As a first cut at getting some efficiency (without doing the numbers) I would set the freezer to max cooling, and then throttle the water flow down until the outlet water was about half way between the inlet temp. and the temp. of the water in the chiller sump tank. From there, regulate the outlet temp. only by resetting the thermostat to where you want the cooling to be. That flow rate should be a fairly efficient one, based on the poor conductivity of the tubing and the capacity of the freezer, as reduced by the pump heating.
"Doing the numbers" reminds me of my "Scotch and Water Diet." [I'd use BTUs for you empire addicts, but as an engineer I am more comfortable with metric units.]
A shot of scotch whiskey contains 75 calories.
Fill a tall glass with water and melting ice. Say it is 200 cc at zero degrees C. Add the scotch.
Your body must gain energy from the 75 calories in the scotch, but it has to heat the 200 cc up to 37C before it is expelled. At the definition of the calorie as the energy to heat one gram (1cc) of water one degree Celsius, that means your body must give up 200X37 calories (7400) while taking in only 75 calories.
Bottom line is that every tall scotch and water you drink reduces your calorie intake by 7325 calories. That beats the heck out of a lot of stupid aerobic exercise! [Where's that tongue-in-cheek emoticon?
After working your way through the diet exercise, does anyone want me to do any calculations on the chiller?
Wright
01 760 872-3995
805 Valley West Circle
Bishop, CA 93514 USA
Diet Calories are not the same as physics Calories... I think there is a 1000 difference so you are actually taking in 75 000 calories of Scotch... but this also don't sound right so just ignore that bit...
I have thought long an hard on the issue of the poor thermal properties of the hose and how to efficiently cool your tank. My solution goes as follows:
Construct a thin glas tank (a chiller-tank) about 20 mm x (height of your tank - 10%) x (lenght of your tank - 10%). Drill two holes into the top of the tank and silcone good PVC fittings into the holes so you can slip your hose over it. The chiler-tank must be water tight for this to work by the way. Then pump the water from the freezer through the chiller-tank that is now suspended in the main tank. Glas has much better thermal properties than the plastic hose and should serve a much better chiling effect. You may not need a very tall or long chiller-tank because glass is an excellent heat exchanger (compared to plastic)! Some experimentation will be needed.
The best option is perhaps stainless-steel tubing that is hung in the tank and water pumped through it. I would still use the plastic hose as a go-between the freezer and stainless-steal tubing.
This is just my 2c. I'm a biochemist not engineer.
Cheerio
What's the point of that? Heat from the 1st pump is displaced within the freezer, only to be heated up by the 2nd canister pump. All motors displaces heat, be it mounted above the canister or within the sump.
I'm puzzled why you'd want a 'strong enough' flow, when it's the flow of water through the hose, while it's in the freezer, that makes the difference. In page 2 of the thread, I've already said, "Similar to concepts that apply to UV sterilization, it's the duration of exposure and flow-rate within the unit that makes it effective."
I believe it would have been better if you've just taken enough length from both ends for the connection and left the rest intact, ie. without loosening the coil. Since the tank is filled with water, the weight of the water within the coil doesn't make much difference, not significant enough to kink the hose, I think.The hose later started to kink when we fillled it with water. So we decided to loop it lying down instead.
Did you have another thermometer for reference?The thermometer registered a shockingly low temperature of 26.6 degrees Centigrade
You'll need some time to tweak the freezer's setting but for a start, set it midway, instead of the coldest setting... it'll be interesting to see your fishes in thermal undies!
I'm back & keeping 'em fingers wet,
Ronnie Lee
Tyrone,
You sure know how to take all the fun out of another ridiculous diet.
Food calories are heat-of-combustion calories, and those are, by tradition, kilogram calories. You are correct that the difference is exactly 1000 and the net caloric intake is 75,000 minus the 7400 (in gram calories).
Switching back to Martinis, since my scotch diet is about as useful as a low-carb diet.
Wright
01 760 872-3995
805 Valley West Circle
Bishop, CA 93514 USA
KL, where did you get the nice bulkhead fittings on the lid? Love the color of the box! My next car will be that color!My question is: if you throttle down using just one pump, would the water have a better chance to interact with whatever plasticizers are in the hose? Or is it decreased by having less water pumped per minute?
I woke up this morning at 6 am expecting to see a block of ice but the thermometer read 26.5 C. Shucks. I checked the freezer and it was pretty warm on all sides on the outside. I checked the water inside the tank inside the freezer and heck, it isn't even cold although there's a lot of ice on the walls of the freezer.
At about noon, I called home and my maid said the thermometer read 25.9 C. Whoopeee!!! I thought. It's working!!!! Considering that its pretty hot today and the fact that the fans are no longer running, 25.9 would be pretty good.
Thanks for all the suggestions, folks. I'll answer your questions when I have more time but for the moment, I will just explain why I'm using 2 filters. One external cannister filter alone can't pump the water through 50 metres of hose. We tried but it won't work. Even with 2 filters, the flow rate is just slightly better than a trickle.
I thought about the chiller when I'm at work and I think I know what's wrong. I should have chilled the water inside the freezer first before pumping the water from the tank through the hose. Currently, what's happening is my freezer has to chill not just the water inside the chiller tank but the fish tank as well. That would mean chilling more than 400 litres of water. The reason the water inside the chiller isn't cold is because the temperature would be about the same or equal to the temperature of the water inside my fish tank. Although they seem to be 2 entities, the water inside the chiller tank and the water inside my fish tank is actually one because they are related to each other by the hose which runs from the fish tank, through the freezer and back into the tank again. I hope you all understand what I'm trying to say. Frankly, I'm just as confused myself.
But this is what I'm going to do.
It's about 4.30 pm now and right after I send this post, I will switch off my filters. In other words, I will let the freezer chill the water inside the chiller tank first. When it's pretty cold, close to freezing, I will run the filters and let the water from my fish tank flow through the hose. It should chill the water in my tank faster this way. If it doesn't, well, then it's back to the drawing board again.
Loh K L
Okay, folks, the filters have been switched off. It's now 4.32 pm. The thermometer reads 26.0 C. I expect the temperature of my fish tank to climb. It has to get worse before it gets better
I checked the temperature of the water inside the chiller tank and it's 24.0 C, just slightly below that of my fish tank. I expect it to go much lower very soon, now that the filters are off.
Loh K L
Kwek Leong,Okay, folks, the filters have been switched off. It's now 4.32 pm. The thermometer reads 26.0 C. I expect the temperature of my fish tank to climb. It has to get worse before it gets better
I checked the temperature of the water inside the chiller tank and it's 24.0 C, just slightly below that of my fish tank
I think if you have another digital thermometer, better if it's the same model as what you're using now, you wouldn't have to open the freezer's lid to check the temp and lose lotsa 'cold' air.
Before you fit it to the freezer, verify/compare the readings, just so you know how far off each unit differ.
To help speed up the cooling water in the freezer, drop in a bag of ice from 7-Eleven.
Seriously, I can't imagine an Eheim canister not able to push water through a coil of hose. Either you have a kink in there somewhere or possibly something obstructing the flow (clogged filter media perhaps?). Switching off both canisters sorta defeats the purpose of the whole exercise, I think.
If James can do it with a measly bar fridge, I can't see why your freezer wouldn't work!
I'm back & keeping 'em fingers wet,
Ronnie Lee
Hah!! It will work, my friend but it's going to take a longer time, that's all.If James can do it with a measly bar fridge, I can't see why your freezer wouldn't work!
I was just as puzzled too when one Eheim 2215 couldn't push the water through 50 metres of hose but I didn't have time to check everything yesterday. To check if the problem laid with the filter media would mean emptying out the filter which I was reluctant to do. The problem, I suspect, lies in the diameter of the PVC hose I'm using. It's slightly smaller than an Eheim hose which would mean the volume of water travelling through the hose isn't constant. For the Eheims to work effectively, the hoses should be of the same diameter but I couldn't find a PVC hose that's of the same size.
As for the thermometers I'm using, they could be off but it isn't much. I checked the digital one against 2 analog thermometers and the difference was about only half a degree C. It's 8.15 pm now and I just checked the water inside the chiller tank. The temperature there is now
15 C. Brrrr, it's cold. And I think that proves what I suspected.
To chill the fish tank, I have to chill the chiller tank first. The theory is that whilst the freezer is chilling the chiller tank, the fish tank is warming it up. The fish tank is much bigger so although the freezer is effective, it will take a long time to balance out the temperature in both tanks. It will work but it's going to take a longer time, that's all.
The filters won't be switched off forever. When the temperature in the chiller tank drops to about 10 C, I will start the filters working again. My fish tank is still about 26.5 C now but that's because I cheated. When I switched off the filters just now, I started the fans working again
Loh K L
Bill, are you referring to these fittings?
They're cheap and easily available in hardware shops. If you can't find them in the US of A, let me know and I'll send some to you. As for the Singaporeans following this thread, here's the address of the shop:
Chuan Hup Huat
Block 809 French Road
#01-184
Kitchener Complex
Singapore 200809
Melvyn bought the fittings for me. He made the mistake of not buying the washers as well so the thing leaked when we started the water running. Make sure you pick up 3 washers for every coupling. It looks completely water-tight but it isn't so without the washers. The same shop also sell all sorts of hoses. It's where I got the PVC hose.
Loh K L
Tyrone, thanks for the tips but I'm afraid it's too late to rig up a chiller tank like the one you described. The one I'm using now is just slightly smaller than the freezer's compartment. It's about 57 litres. Here's a pic:
Poh San who called me on the phone this afternoon suggested something which he calls thermal plates. I have no idea what Poh San intends to do but he said he's going to show me the diagrams later. He said it will help to chill the water inside the hose effectively.
Loh K L
Wright, I don't know what's the watt rating of the freezer as the specs don't specify that. I tried to check the rating on my Eheims too but the words are all worned out. The numbers aren't visible anymore.
In any case, I doubt the heat generated by 2 Eheims can be high enough to neutralise the chilling effect of a freezer. I know nuts about electricity but hey, the freezer's a lot bigger
As for the conductivity of the PVC hose, I'm aware it isn't as good as aluminium or anything made out of metal but we have to be wary of the costs too. If I have to buy hose from Canada or use something made of metal, the costs may become so high I might as well just buy a chiller.
Loh K L
2215
for tank size up to 350L
Pump output 620L/Hr
Filter circulation 510L/H
Delivery head 1,80 M/WS (water column)
Filter volume 4L
Kwek Leong, I have a 1048 at the lab that you can borrow. It's output is rated slightly lower than your 2215 but if the 1048 can do the job, I think the bottleneck is obvious.
1048 Centrifugal pump
Pump output 600 L/H (158 U.S. Gal/H)
Delivery head 1,50 M/Wat.Col. 4 ft. 11 in./Wat.Col.
Power consumption 10 W
Hose connection (suction side) Ø13mm (1/2")
Hose connection (pressure side) Ø13mm (1/2")
I don't think the slightly smaller hose diameter is the culprit. Let me know if you want to pick up the pump.
I'm back & keeping 'em fingers wet,
Ronnie Lee
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