Backyard Aquaponics
A place to discuss aquaponics

Hi there!

This is my first post. We've been studying this wonderful world for months, learning, taking notes, printing out downloads etc...

I finally registered a few minutes ago and will continue to read through as many threads and posts as I can (I'm like a sponge soaking up and sorting through all the information and links shared here)

Once we begin actual building, I will share all with photos (planning some interesting features in a really tight space!)

Thank you to all who have posted helping others!

We just purchased two IBC's used only once with food in them (The look like new!) We also have a 1,500 gallon koi pond we will be redesigning the filters for, emptying out the decorative rocks to increase water volume ...(Sorry, I really do have to learn to live with metric! I'm a prototype designer by trade and all my clients live in the "decimal world".)

We get some fairly cold winters here with hot summers. As I am designing the plumbing and systems for our tanks and ponds, I REALLY want to offset any heating expenses with solar (contrary to what most believe, we do get a fair amount of sunshine even when it's cold.)

I've researched like crazy and totally prepared to build panels from scratch (although keeping my eyes open for used pool or home solar water heaters...

As I've only recently learned about Craigslist, I have been searching through their many categories and stumbled onto a bunch of used auto radiators... The efficiency of these items is astronomical when reversing their purpose from cooling, to heating up fluids...

My problem is, I know antifreeze would not be the best thing for fish or plants and as most are used, my questions is:

Can a used auto radiator be flushed/cleaned in such a way to make it safe for fish and plants?

Most are aluminum (although concerned about brass, but I also work in metal and since these are not under high pressure, I'm pretty sure I can bypass the brass... (Are brass fittings bad/toxic for fish?)...

Any helps (especially from any of you who have tried this approach), would be mot helpful.

Thanks!

Richard

I dont know enough about the chemistry to say if antifreeze can be treated but i dont think i i would try.

While i would say most metals should be avoided in aquaponics... copper, brass and nickel are the worst. Most consider stainless steel to be safe.


Maybe you can use the idea and the design to build something like a car radiator out of ideal materials?

aluminium is toxic to fish, the copper in the brass will be too.

Most radiators I've seen are made of Copper, not Aluminium (or Aloominum as you say in the USA ). Aluminium reacts with acids and alkalis, so presumably would tend to slowly corrode/dissolve in most AP water that was not neutral @ pH7.

What you need is a heat exchanger, submerged in the water you want to heat, and made of a fish-safe material.

You May also struggle if directly passing fish water through the
radiator with blocking from solids and biofilm.

Thanks guys!

I was just trying to maximize heat exchange... Not too concerned about solids (other systems for removing and using in our huge backyard dirt "farm").
CPVC looks like the way I will be going. Probably going to look into some extrusions I can glue on to create "cooling fins" (Will work in the opposite direction extracting heat into the tubes.

Planning on a tin backing to help create more heat (Gluing the plastic heat exchange pipes to the tin). Summers will not need the efficiency as much as spring and fall. I'll need to shut down and drain in the winter though.

So... bottom line: no metals except stainless!

Got it!

Thanks again!

Richard

PS: Obsessed? Ha! My "schooling" takes place almost every morning starting around 3AM! This morning's classes were on benefits, uses and how to maximize growing Duckweed! (Our rabbits and chickens will go nuts! And will provide sustainable feed for Tilapia...

So to reiterate what may have already been said. The radiators on their own closed loop filled with propylene glycol, not ethylene glycol, brought to an insulated vessel filled with propylene glycol, with independent coils of tubing from both the radiators and your ap system. I read somewhere that vermiculite holds heat very well too, so perhaps instead of a glycol, fill the tub with a water and vermiculite mix. That would certainly keep temps stable.