Larry Lunsford

Rocky Mountain Koi Club

Before you get the wrong idea, just let me set one thing straight: NO, WE DON’T EAT THEM!!! The Koi B-B-Q is a cheap device to turn your gas grill into a pond water heater. If you have an occasional need to heat your pond and you have a gas BBQ grill, then this may be a project for you. A typical propane BBQ grill is rated at 30,000 to 50,000 BTU/hour which is enough to add quite a bit of heat to even a large pond. The cost of propane in little BBQ grill tanks is relatively high, so I wouldn’t plan to use a Koi BBQ for long term heating of your pond.

I built my Koi BBQ to use at a recent RMKC Koi show. We were planning to do water changes through the show and I was concerned that the water fresh from the hose would be a lot colder than the water in the tanks that had been out in the summer air for a couple days. The Koi BBQ did a great job of heating the water (although it wasn’t really needed).

Before you run off to the hardware store to buy parts, I need to give you an important note:

Do not use the Koi BBQ with water that is the least bit acidic (low pH). Acidic water will dissolve copper from the pipes and your Koi will become ill and possibly die. Only consider using this device if your water has a pH of at least 7.5 and is well buffered (has a KH of at least 120ppm). You can increase the buffering of your pond with baking soda.

Building the Koi BBQ: The Koi BBQ is simply a coil of copper pipe that is sized to fit inside a gas BBQ grill. I used ¾" pipe which is fine if you’re not concerned about maintaining a high water flow rate. If you need faster water flow, use 1" pipe. I would suggest using a separate pump for the Koi BBQ so that it does not interfere with the flow through your filter.

Get your materials. The adapters to connect to garden hoses aren’t easy to find in all the possible permutations, so find adapters that are as close as possible to what you really want. Next, find the appropriate adapters to go between your garden hose adapters and your pipe. Get pipe and a bunch of 90° fittings (get a couple extra just in case). Cut all your pieces of pipe and start soldering. My Koi BBQ is 18" x 13" and has 12 loops of pipe. You need to adjust dimensions to fit your BBQ. I soldered up a bunch of U’s first, then soldered the U’s into a finished coil. I included pieces of pipe that hang down the front of the BBQ and attach to the garden hoses. I did this to keep the rubber hoses well away from the heat of the BBQ.

Materials:

    ¾" pipe 40’ $28

    90° elbows 52 $17

    Garden Hose Adapters 2 $5

    Total Cost $50

That’s it – you’re ready to BBQ for your Koi. Keep a close watch on you pond while using the Koi BBQ. Don’t just turn on the BBQ to high and walk away. A little tank of propane can heat up a 1000 gal pond by 60° so be careful. Happy BBQ’ing.

Koi