Pond Boss Forums GENERAL QUESTIONS Property Projects & Construction Garden pond siphon cleaner

My 20x18x5’ garden pond needed a good clean out. I live on a hill, so I have gravity to my advantage to create a siphon to clean the pond out. It worked fantastically well, better than expected. I will try and describe how I made it:

Parts List:
80’ of 1.5” flexible spa tubing, length is optional, but you should have at least 2’ of drop from the lowest point you need to drain to.
Two threaded 1.5” PVC ball valves
Six 1.5” threaded to barbed adapters
Two barbed to 1.5” smooth adapters for PVC pipe
One 1.5” to 3/4” barbed T
2’ of 3/4” vinyl tube
3/4” brass female hose fitting
Hose valve
Low profile shower drain, 1.5”
At least 6’ of 1.5” PVC pipe.
Bucket with large holes cut in the side. This acts as a water reservoir to prevent air from running back up the pipe from the drain end when combined with the shower drain installed in the bottom.
Many of these parts on Amazon come with pipe clamps, but you may need a couple more. They didn’t seem to help much as the barbed fittings into the spa tube is impossible to remove later.

I cut the spa tube into a 18’ section, 1’ section, and a 3’ section. The 18’ goes into the pond with a barbed to smooth adapter on the free suction end. This limits object size it can pull through and allows putting on a length of pipe to reach further. After the 18’ section is the first ball valve. Then the one foot section, then the T adapter. Then the 2’ vinyl and hose adapter on the 3/4” fitting. This should be the highest elevation point on the siphon. A garden hose from house water is attached here with a valve for siphon pre-charging.
Next is the long piece that heads downhill, 58’ in my case.
At the downhill end comes the second ball valve assembly. Then the 3’ section, ending with the barbed to 1.5” PVC adapter.
Install the shower drain into the bottom of the 5gal bucket with holes.
A length of 1.5” pvc to join the shower drain to the tubing with the adapter fitting. This will need to be glued as the pressure can be high depending on elevation change.

To pre-charge, close the downhill valve, open the top valve, then fill the spa pipe with the garden hose. Leave the 18’ end in the pond where it will bubble as the pipe fills. Once it stops bubbling, it’s ready. Close the valve on the garden hose. Make sure the vacuum end is under water, then open the lower elevation valve. The siphon is running!

I have a 9’ drop over that distance, and the suction was very strong, but not dangerous. There were a few times when the shower drain plugged with debris, but I was able to clear the plug by closing the top 1.5” valve and turning in the garden hose.

The expense was the spa tube, $2 a foot on Amazon. However, a lot cheaper and better than fiddling with a trash pump.

Caution though, don’t leave the garden hose valve open when running. The strength of the siphon will pull significantly on your house water supply.

I typed this on my tablet, so sorry about the mistakes.

This system is likely too small for most ponds here, and anything larger with more elevation or pipe diameter would probably be dangerous. However, for larger garden ponds it is wonderful!

Thanks for taking the time to type up that tutorial.


P.S. As to removing the barb fittings: I have had good success on problems like that by grabbing a pair of work gloves and then stealing a nice hair dryer from one of my daughters. I have not yet melted any type of plastic hose with the hair dryer on the "high" setting. Heating the spa tubing from the outside should give you enough expansion AND flexibility to pull it free of the barb fittings.

I have done similar siphons with different size pipe as needed, depending on the time and pond size.
I only used solid wall pvc pipe and fittings as needed because it is considerably cheaper then the spa hose, a short chunk of the spa hose would be nice in some of the elbow spots as it gives you a variable degree of bend. but I always just glue the spa hose into the fittings like regular pvc pipe, seems to be easier then barb and hose clamp fittings and less chance of it drawing air.

The good part of the system is it coils up and fits in the back of the Subaru. My dad also needs to drain his pond, so the portability is nice.
Straight pipe is half the price, but handling it all seemed like a pain in the butt. The end in the pond though needs the flex for cleaning the bottom of muck. I fibbed about the length I have, only 6’, and it needed to reach the other side. I used a straight pipe to add another 6’, but that straight was a PIA to manage around obstacles. I had to work around lilies and large stones.

Dealing with the goldfish koi hybrids deserves another thread. Those were the primary reason for draining it. I couldn’t catch the buggers otherwise.

I have a couple of small ancient water holes like that. I once decided to siphon them to get my tractor in to clean and deepen them after a drought. I was half way through the first one when a rare flooding rain hit. Luckily, I had not left the tractor in the hole when I finished scraping for the day.

Haven’t messed with them since.

I believe that leaving construction equipment in a low spot is the best method yet invented to guarantee torrential rains!

Using the flex hose, if you are planning on reusing and or transporting it, makes a lot of sense, I was talking about just an occasional pond that I may be wanting to clean out or just lower the water for overflow or spillway work.

I always use a check valve on the inside end to hold water till I have it all full and open the quarter turn valve on the outside lower end, and away she goes, amazing how much water it will move in a short period of time.

Am dealing with one currently that is lower then the ground on the back side of the dam so there's no way to siphon it, had to pump it down pretty much empty then work around the water thats left, just a small pond tho we are cleaning the muck out of and stealing fill for a house site.