My plan to wash 3 yards of sand

[combatwombat]

Okay, so I really want to use sand instead of gravel for the horizontal surfaces of my pond. Have seen lots of youtube videos of recreation ponds using sand in the pond and partially in the pond as a beach area. Not sure how they deal with all the silt that comes in a load of sand.

I'm calculating that I'll need 2-3 yards of sand to cover all the surfaces.

I've already found a suitable sand using the "bucket test" which means finding a sand that will settle out of suspension within 5 seconds. The problem is that there is silt and super fines in the sand that perpetually cloud the water and make it look muddy. Same is true of every other gravel product, but those are easy to wash and sand is hard to wash.

So, here's my plan for washing 3 yards of sand. I think it's a good one, but happy to hear suggestions for improvement.

1. Shovel sand into bottom shelf of pond. I have a 5x20 area at the bottom of the pond that I can spread several inches of sand across

2. Leave one small area of the bottom without sand and block it off from sand infiltration with some bricks or rocks. This is where a utility pump to pump out silty water will live.

3. Fill the bottom of pond with water. Stir it up to get the silt well suspended.

4. Pump out silty water. Use a utility pump to remove the silty water as quickly as possible.

5. Repeat filling/stirring/pumping process until the water remains clear.

6. Shovel sand from bottom to higher shelves until all surfaces are covered.

This seems like the fastest way to go about it. I've also thought about buying a concrete mixer and washing in that with a hose until the water runs clear, but that would probably make a big mess of sand where ever I do it... and I'd have to buy a concrete mixer.

It's also possible that, once the pond is totally full, the silt would be diluted enough to not matter, but would prefer not to take the chance since I expect my substrate to be stirred up a lot and fixing it after the fact would be kind of painful.

 

[Mmathis]

Anyway you look at it, that’s gonna be a lot of silt-sifting.

 

[Jhn]

Personally, wouldn’t worry about it, it is going to be a lot of work for very little return in my opinion. Have put fine sand in the bottom of my pond in spots, didn’t rinse any of it and it cleared quickly. Have even added sand after the fact and had minimal clouding. I can walk through it at this point without it even kicking up at all.

 

[combatwombat]

Personally, wouldn’t worry about it, it is going to be a lot of work for very little return in my opinion. Have put fine sand in the bottom of my pond in spots, didn’t rinse any of it and it cleared quickly. Have even added sand after the fact and had minimal clouding. I can walk through it at this point without it even kicking up at all.

Wow. Good to know. My bucket tests made me think it was going to turn the whole pond into a big mud puddle.

 

[brokensword]

you'd probably get better results (no silt, etc) if you used coarse mason sand. I'm not a huge fan of sand in a pond as it's not something I want ever getting into the pump or plumbing. Can't remember; is your pump going to be external?

Is the sand purposeful, as in; for the kids? Otherwise, can't see any advantages, esp once any algae gets going, but if it doesn't get stirred up, not going to hurt, either.

 

[combatwombat]

you'd probably get better results (no silt, etc) if you used coarse mason sand.

I have tried coarse mason sand. It's exactly what I'm going to use. It still has a ton of silt in it. But this is just sand in a jar, so probably not as bad once it's mixed with thousands of gallons of water.

it's not something I want ever getting into the pump or plumbing

The actual sand falls out of suspension in like 5 seconds, so I'm not worried about it getting to the pumps at all. Sand won't be located near pumps, either.

is your pump going to be external?

Nope. Submersibles in a vault in the cistern.

Is the sand purposeful, as in; for the kids?

Yeah. And for me. haha. And it just looks really cool. Also, I think it'll make cleaning the bottom of pond easier if necessary. Sunken debris won't be able to penetrate sand and sand is small enough to slip right through a pool net, so I can just scoop junk out of the bottom with a net and sand will fall back to where it belongs.

 

[brokensword]

Sunken debris won't be able to penetrate sand and sand is small enough to slip right through a pool net, so I can just scoop junk out of the bottom with a net and sand will fall back to where it belongs.

good point.

 

[addy1]

10 years later, no pea gravel washing, 38000 lbs, spilled kitty litter on the bottom of the pond. So far no debris has stayed on the bottom. There is a layer of silt, a layer of kitty litter, but no pick up able debris. I quit cleaning the bottom years ago, never got enough stuff out to make it worth while.