I’ve read the advice suggesting that a pea gravel beach would eventually turn slimy due to anerobic decomposition of organic material that works itself deep into the gravel layer with regular foot traffic. But what about large river stones? We have a local quarry that sells heavy baseball sized stones for landscaping. Our beach construction plan is to put down a 12x12 layer of geotextile, create a lip around it with cinder blocks, and cover it with a layer of these large river stones. I understand that this will be pretty uncomfortable underfoot, but our kids are used to walking on sharp rocks in the creek, and we’d rather have a rough beach than a mucky one. The stones are large enough that they won’t shift with foot traffic and the layer will be thin enough that there should be no tendency toward anaerobic slime. Does anyone think this strategy will avoid the issue of a mucky bottom? Or should we just use fine sand assuming it would be more impervious to organic material? Which do you think would require less maintenance? Fish habitat is of little significance to us since this is mainly a swimming pond. Thanks!

I would look for washed plaster sand or reject masonary sand vs. the river rocks. Round rocks ate a PITA to walk on and are constantly rolling underfoot. One twisted ankle and you will be redoing the beach area.....

Sand beaches in fresh water ponds turn into a slimy mess if you don't keep up with the maintenance.

I put a gravel beach in my pond. The dog likes it, the RES like it, and it's good for putting the boat in.
It's also really good for growing FA (snot grass, pond scum, green slime). I rake it if the grandkids
want to get in and splash around. That's not a pleasant task for worn out old man.

Everyone here prefers to use the dock for getting in/out of the water when swimming.

That said, if I was really serious about having a swim beach I'd start by laying some sort of geotextile
fabric, then come with 3"-4" clean chat rock, top that with 3"-4" of man-sand, and stock up on
aquatic weed killer and algaecide.

If sand turns slimy then why top the rock with sand? As I said, I know how hard large stones are to walk on, but that is not my main concern. I’m just trying to achieve a clean beach that is no more comfortable than the average river bank. My question is: will large river stones foster less algae growth than sand or gravel? Thanks for responding!

Pond bottoms grow algae - doesn't much matter what kind of material is down there.

AquaShade, Cutrine+ and a rake are probably your best weapons if you decide to try it.

I think the best man-made swimming pond beach is probably a concrete slab. It's durable, cost efficient, and easy to maintain.

For around $300 (along with about a gallon of sweat equity) a sturdy 12' x 12' x 3" DIY slab can be built using approx 60 bags of ready mix, 300' of 3/8" rebar, and a few 2x4's.

A simple broom finished slab covered with a few inches of coarse river sand can make for a rather comfortable and clean beach

If I were to build one I'd go much bigger than 12' x 12', and to save on the sweat equity I'd definitely use truck delivered concrete.

Around here the concrete trucks will bring 2 yards min. That's prolly around 225 bucks I dont mind the sweatin but I'd rather it come straight from the truck. I love the idea of a beach just dont think I want the hassle.

I pulled this pile off my gravel boat ramp yesterday. It's ~2'x3'x6' of snot grass, sago, and tree leaves. Stinks to high heaven. Pond has been full for one year.

This might help our pool has a creek made up of river stone, it goes hot tub waterfall then creek spilling into pool when pumps on. Most of the time that water just sits there but we run the pump a lot in summer and always once daily for an hour. Naturally that water is chlorinated and is running not most but a lot. I say this because those rocks are the only spot in our pool where we fight algae.