Water Heater element and your fish health ...

[Bob Vento]

After looking over a number of articles on this forum and the internet ... I was wondering why you couldn't use ... say a 4" PVC piece of pipe and a cap that will hold the hot water tank heating element centered on one end and a screw cap on the other.

Fill up the chamber with water and screw on the cap, waterproof and drop in fish tank. Plug in and heat the water inside the 4" PVC chamber. The residual heat would radiate out from the PVC pipe and heat your fish tank without exposing the fish to the heating element at all.

Does this sound like it could work? Just sayin' !

Bob

[Flemming Funch]

I'd guess that PVC isn't a good heat conductor, so a lot of energy would be wasted on the way through it. Stainless steel would be a lot more interesting.

Then again, if the walls of the PVC pipe are really thin, not like the thick stuff I have here, maybe it is fine.

[Jon Parr]

Try it, bob. My first instinct would be that the heat expansion, and indeed possible boiling of water surrounding the element would wreak havoc on the PVC, or any tube material for that matter. And the difficulty of safely waterproofing the wires. Simpler would be to make a barrel heater with the same element, and circulate the hot water thru a coil of PEX either in or under the FT. The barrel could be insulated and open go the atmosphere to prevent thermal pressure problems. Gee, its starting to sound like an old water heater with a Hydronics (radiant heating) circuit, isn't it?

[Jim Troyer]

Hi Bob

I think this would work with one small modification.  If you are using the 4" pipe as a protective barrier to keep the fish a safe distance from the heating element by making the 4" pipe basket like by slicing it with a skill saw many times to let the water pass through.  This would eliminate melting of the PVC I've seen with other attempts.

Thanks for posting your idea; it definitely holds potential

[Jon Parr]

Jim, I think the PVC pipe is sealed to prevent the fish water from coming into contact with the zinc/copper elements used for water heaters (metals toxic to fish), and also the calcification that occurs on the element itself from the nutrients in the fish water (build-up destructive to element).

[Vlad Jovanovic]

@Bob...I guess this morning I had assumed you meant this...http://community.theaquaponicsource.com/forum/topics/diy-heater-sub...

but here it is in case that wasn't the info on this site that you were referring to...

Using a different breed of fish may (or may not) make this rather obsolete though...the tilapia doesn't taste that good does it?

[Jim Troyer]

Gottcha Jon,

I should have mentioned the metals issue on run of the mill heating elements.

Be sure to use a Stainless Steel heating element!

Check out Vlad's link to the proper heating elements and a nice clean way to create a heating unit

[Bradly]

Bob

I just made this yesterday... because it's low cost. I'm going to put a "cage" on end and clamp it to the pvc to keep fish away from the element.   This water heater element is 1200w and is small...found at home depot.  The Johnson A-19 control I'm hearing is about $20-30 (I got from a friend)....so altogether $50 ....plus a 12 Gau Extension cord.

The heating element is 1" thread....element is actually screwed into a 1" pvc female adapter.

I'm not recommending anyone make or use this...I'm just saying that I'm gonna!  :-)

[Bob Vento]

Bradley,

This looks interesting however, I don't think it is the heating element coming in contact with the fish that is the issue but the chemical reaction of the element when it's composition deteriorates, over time in the water and creates other elements in the fish tank water.

Bob

Bradly said:

Bob

I just made this yesterday... because it's low cost. I'm going to put a "cage" on end and clamp it to the pvc to keep fish away from the element.   This water heater element is 1200w and is small...found at home depot.  The Johnson A-19 control I'm hearing is about $20-30 (I got from a friend)....so altogether $50 ....plus a 12 Gau Extension cord.

The heating element is 1" thread....element is actually screwed into a 1" pvc female adapter.

I'm not recommending anyone make or use this...I'm just saying that I'm gonna!  :-)

[Bradly]

10-4 Bob...  but me and my family drink water from the heater element in our water heater, and without heat those fish will never make it.  I'm getting ready to cycle up for a test run in a week or so (in prep for full blown operation in the spring) temps where I live drop at night.

Bob Vento said:

Bradley,

This looks interesting however, I don't think it is the heating element coming in contact with the fish that is the issue but the chemical reaction of the element when it's composition deteriorates, over time in the water and creates other elements in the fish tank water.

Bob

Bradly said:

Bob

I just made this yesterday... because it's low cost. I'm going to put a "cage" on end and clamp it to the pvc to keep fish away from the element.   This water heater element is 1200w and is small...found at home depot.  The Johnson A-19 control I'm hearing is about $20-30 (I got from a friend)....so altogether $50 ....plus a 12 Gau Extension cord.

The heating element is 1" thread....element is actually screwed into a 1" pvc female adapter.

I'm not recommending anyone make or use this...I'm just saying that I'm gonna!  :-)

[Jon Parr]

Bradley, fish are different than humans. If you are using a standard heating element, you will get a metal toxicity that will kill your fish. It will take a while, but in a couple of months you will get unexplained fish death, one or two at a time, until they are all dead. Besides physiology, the primary difference between our drinking water being heated by a copper/zinc element and the FT water is the presence of oxygen. Our tap water is anoxic, and thus limited reaction can occur with the element in a water heater. However, circulating oxygen rich, bacteria rich, acidic water across the same element allows the metal to enter the water. The other big difference is the fact that hot water that we drink has made a short stay in the water heater, only ONE time, constantly being replaced by fresh water. FT water however, doesn't go anywhere, just recirculates and accumulates the products of oxidation.

[Vlad Jovanovic]

Not to mention the difference in pH between most tap water and your AP system...According to a study done by D. J. B. Dalzell and N. A. A. Macfarlane. On Brown Trout. Published in the Journal of Fish Biology Vol.55 Issue 2 pages 301-315... 

the lower the pH (below neutral) the deadlier the metal...even something as relatively as "benign" as iron...Like Jon says, add oxygen to the mix and recirculate that water...Copper, lowish pH, oxygen...might be a recipe for 'head scratching mysterious fish kills' a month or two down the line...

[Bradly]

Oh man....I had no idea.  The element itself looks like stainless steel...maybe it is.  I'll double check it. 

If it is stainless steel then I should be good right?

 

Thanks Much Jim,Bob,Jon, and Vlad ...

 

Boy...isn't there any part of this that's easy ??  :-)

(And I haven't even cycled up the system yet) !!