View Full Version : Spindrifter Clone by Harveythekoi

09-18-2004, 03:46 PM
To be fair and avoid any arguments I’ll admit the Spindrifter drains are the best available aerated drain on the market. They are also the most expensive. As this ties in with my attempt to build a “proper” Koi pond on a budget I’ll lay out what I did to save a few bucks better spent on other things. My design incorporates some of the better features and eliminates some I don’t find useful.

I started with a standard 4” domed bottom drain for $55 and added a 9” diffuser from AES for $19 and a ¾” non-springed check valve also from AES for $8. Those are the major parts totaling $82.

I went with the ¾” check valve because it’s the thread size of the diffuser. I also like the fact that the check valve is not buried under the pond. Should it fail I could replace it. I then enlarged to 1” piping both for stability at the base and volume of air from the pumps. To set the height of the dome I just use a different ¾” nipple length. These parts will form the shaft the diffuser/dome attach to. Diffuser, check valve, ¾” nipple, ¾” thread to 1 slip reducer, 1” slip/NPT coupler, 1” close nipple, rubber washer, 1” slip/NPT 90°. The PVC fittings added up to around $8 for a total of $90 now.

The various epoxies and glues I tend to use ran around $20 but will handle both drains so add another $10 for a total of $100

I’ll consider my labor as overhead as I’m gonna be tinkering no matter what.


http://members.cox.net/g.a.k.-2/Spin Clone10e.jpg

09-18-2004, 03:51 PM
As you can see in the top pic the diffusers have a serrated lip around the edge for unscrewing it to replace the membrane. With this lip lower than the top edge I decided to make the dome fit flush with the top. I measured for center and cut it out with a jig saw. I cut short and used a rotary rasp to finish enlarging to size for a tighter fit. The rasp is pictured above, I just used my drill to run it to keep the RPM’s low enough to control it better. In the second pic with the dome upside down you can see the molding marks in a criss cross pattern that show I got it fairly well centered. In the third pic you can see where I drilled the hole all the way up the shaft of the diffusers. The original was fairly large till it got to the top then it got tiny. The check valve also have a small torpedo like protrusion that holds the internals together. I wanted as much room around this as possible.

http://members.cox.net/g.a.k.-2/Diffuser Checke.jpg

http://members.cox.net/g.a.k.-2/Spin Clone17e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone21e.jpg

09-18-2004, 03:52 PM
Here’s the dome being glued to the diffusers. I decided against the one Polyurethane glue pictured above and went with the one in the pic. It’s a self leveling brand. I didn’t feel comfortable with splitting one tube between both so I used a whole tube on each, add another $5. I taped the dome to the diffuser to both hold it in place and seal it while the sealant dried. I wish they had it in black but no one will ever see it besides me. I threw the weights on to make sure it sat level. As a warning to anyone trying this, use the tubes half for each at a time. This will allow it to cure faster and then use the other tube across both to finish. It’s been a week and mines still not fully cured. They wont go in for some time so for me it doesn’t matter that much.

http://members.cox.net/g.a.k.-2/Spin Clone18e.jpg

09-18-2004, 03:55 PM
Here’s one of the issues with the Spindrifters. The hose going to the diffuser. Many claim that the one that comes with it is too small. I have seen where it was modified with a larger hose but always thought that would interfere with flow too much. My solution is to bring the air directly up from the bottom so the only obstruction is the center shaft.

So I drilled the bottom of the drains with an 1¼” hole saw. This will fit the 1” nipple tightly through it. With the nipple threaded to the 1” coupler I put the rubber washer on it and inserted it through the hole. Then I threaded the 90° on to clamp the whole thing together. It is very sturdy just like this. But because it’s going in the bottom of the pond I wanted to make sure there were no leaks. The existing support tube for the dome went into a fitting area in the bottom of the dome. My 1” coupler fit in there with a ¼” or so gap around it.

http://members.cox.net/g.a.k.-2/Spin Clone15e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone22e.jpg

09-18-2004, 03:57 PM
I used the marine epoxy to seal this entire void. Both for stability and strength. I found a syringe at Wal-mart for measuring oil for 2 cycle engines. It was large enough to squeeze out the contents of the epoxy and mix inside. Then it was easy to neatly (yeah right) inject it into the small void space. I worked it in with an end piece from a large tye wrap that I used for another project (more on that later).

Side note: This epoxy is great for pond stuff. It remains somewhat elastic stretching up to 30%, works under water and bonds to most things. Is does say it’s not recommended for polyethylene or polypropylene.

EDIT: I did find an easier way to apply the epoxy on a later project. Take a sturdy plastic bag, ziploc's work well, empty the contents of the epoxy into it and knead till ready. Then snip off a small piece of the corner and use it like a pastry icer. No mess and much cheaper.

http://members.cox.net/g.a.k.-2/Spin Clone12e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone23e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone24e.jpg

09-18-2004, 03:58 PM
Here’s the neatly, LOL, injected epoxy. Good thing this stuff wiped off with a rag.

http://members.cox.net/g.a.k.-2/Spin Clone25e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone27e.jpg

09-18-2004, 04:00 PM
One other small issue with the Spindrifter.

If you noticed my 90°’s are aimed in different directions this was intentional. Most people would probably have their air pumps in the same area as their filters so no issue there. I have to be different, go figure! I have a space under the viewing deck that will house the air pump and then allow me to switch the air on and off for viewing. I could have run the wire all the way to the filter pit but it seemed a waste to do all that and add to the air pipe length.

I also added the epoxy putty around the 90° on the bottom. Again for strength and stability. Was it necessary? Probably not, between the epoxy inside and the rubber washer I doubt this would ever leak. But, again, for strength and stability under the pond it’s cheap insurance.

http://members.cox.net/g.a.k.-1/Spin Clone13e.jpg

http://members.cox.net/g.a.k.-2/Spin Clone29e.jpg

09-18-2004, 04:00 PM
Some of you may question all the threaded fittings. They aren’t really a concern for me since I started using a product called Plasto-Joint stik. This stuff is great! Specifically made for plastic threads it seals excellent. Been using it since I started ponding and have never had a leak on a threaded joint. The best part is you can remove fittings easily as it never hardens.

http://members.cox.net/g.a.k.-1/Spin Clone19e.jpg

09-18-2004, 04:01 PM
So for a little over $100 each I got two well designed ( in my opinion) aerated bottom drains. Not too bad considering 1 Spindrifter cost more than that. The money saved is paying for the 2 pumps to run the bottom drains. I plan on the Sequence 750 series SEQ3600SEQ12. With feed and return piping it should average out at 3000 GPH.

Some may argue that the Spindrifter is molded with a thicker plastic and therefore sturdier. That’s true but I intend to surround these with a concrete ring about a foot out in diameter to hold them in place and protect them. Steve C’s idea of the double street 45°’s will be used to allow more room for concrete on top of the exit pipe. I’ll slope the concrete slightly towards the drain and attach the liner on top of that giving it a very smooth and even surface right before the drain.

I think I covered everything, if not please feel free to ask.

http://members.cox.net/g.a.k.-2/Spin Clone30e.jpg

09-18-2004, 05:04 PM
I'll toss it in a bucket of water then. They wont go in for a while so I'm in no big hurry. I'll start a thread soon on the new pond progress and you'll see why. I was sure they had black just not at the local HD.

EDIT: I got the drain from Gene at Koivillage. I hear he's also selling the diffusers now.