Help me figure out how to keep the bottom of my gravel pond clean... automagically!

[combatwombat]

This is hypothetical because I don't actually have a pond yet. Just a big hole in the ground (see photo below). Bottom shelf is about 4' deep.

I'm trying to design this to be a light load fish pond that my family can also splash around in during the summer. There will be an intake bay and a wetland filter.

My liner is here, but I haven't put it in yet because I realized I haven't really thought about the bottom of the pond and if I should do something to keep it clean. I plan to either put in gravel or flagstone at the bottom.

My primary goal is for this pond to stay as clean and clear as possible with as little ongoing maintenance from me. I never want to drain and clean this thing if I can avoid it.

Over the last few days, I've pondered and researched several possible solutions to keeping the bottom of the pond debris free, all of them with their own pros and cons.

1. Install a bottom drain. I don't really like anything about the idea of a bottom drain except that it seems to work really well. I think it would be difficult to incorporate properly with an intake bay and is not really compatible with a gravel bottom. But I guess it would work okay with flagstones. I don't want to deal with settlement chambers or a sieve I have to clean all the time, though. I think this option is basically a no go for me.

2. Put jets near the bottom to push water up. Get some flow going down there and hopefully direct anything that makes it there back towards the surface where the skimming action of the intake bay can get it. Major benefit is that it's pretty easy to install. Downside is that I think you'd have to have a hell of a pump and some big pipes to accomplish any real sweeping activity with the head pressure you'd get at 4' deep. I think jets are normally installed near the surface for that reason.

3. Under gravel suction grid. I've seen this written about several times by folks who say it works amazingly and can be accomplished with low voltage air lift pumps. so low electric overhead. Would be easy enough to install, but not really compatible with an intake bay and a submersible pump. Think it would require me to get an external pump to properly control flow.

4. Under gravel pressure grid (bog on the bottom of the pond). I've also seen this done with an Aquascape snorkel and centipede. You're basically creating a bog at the bottom of your pond. Pretty much the same as the suction grid, but you're blowing water through it rather than sucking. This would work with an intake bay just fine. However, a snorkel to access the bottom with a pump is out of the question in my case. I don't want a huge pipe sticking up in the middle of my pond.

Honestly, at this point, I'm kind of thinking I might just do nothing and hope for the best. Keep It Simple, Stupid. Seems to work pretty well for a lot of people. Why not for me?

If you're a big fan of one of these systems and see how it could for a pond like mine, I'm all ears. Or if I've missed an option that I should consider, let me know.

 

[Lisak1]

I'm going to go with KISS. My gravel bottom pond is always clean - never have an issue with muck or any other build up. And especially if you'll be in the pond walking around, you'll be stirring things up and that helps a lot.

 

[combatwombat]

I'm going to go with KISS. My gravel bottom pond is always clean - never have an issue with muck or any other build up. And especially if you'll be in the pond walking around, you'll be stirring things up and that helps a lot.

What do you think about flagstone vs gravel? Flagstone seems nicer on the feet and easier to clean if needed, but might be extremely slippery once it gets covered in biofilm?

 

[brokensword]

sort of seems like you're trying to get the best of both worlds; pool and pond. If you swim in a natural pond/lake, you're going to take your chances with what's below. Sometimes it's clear, often not. So, minimally, your pond is going to be like that. The bog filtration will help parameters but won't do much for any algae-on-surface problems as that requires lots of floating plants to help you shade the area. If you do this, you'll probably get minimal debris on the bottom, unless you're getting it from what the wind gives you.

I'd not put jets on the bottom and push upwards; that's a sure way to make clarity go downhill.

The other 2 methods I'm not familiar with so have no opinion other than to say I too tend to like the KISS method most of the time.

I would imagine flagstone would be more gentle on the feet. If you could get some sort of stone that was more rough than smooth, it might help with traction, unless the biofilm curtails that idea.

An idea might be to do as public beaches do; put down a layer of sand. Maybe 4" or so? You'll be less likely to get that slippery feel unless you let the mulm build up but even then, your weight will push through that (as in a natural pond) and the sand will give you a more forgiving surface both in traction and feel.

Hope this helps.

 

[Lisak1]

Flagstone will indeed get slippery, but I've seen people do it in rec ponds.

We grew up swimming in quarry ponds and natural lakes so we never worried a whole lot about what we were stepping on. When I get in my pond now I wear Crocs or water shoes - helps with any slip and slide issues. But I've walked barefoot on the gravel, too and it's so smooth it's really not an issue.

I always get a bit wary of sand - I wonder if you would end up stirring it up to the point that it would make things cloudy. But no experience there. I do remember when we would swim in lakes that had sandy bottoms, you didn't want to dig too deep in the and - it got stinky very fast.

 

[BKHpondcritters]

What do you think about flagstone vs gravel? Flagstone seems nicer on the feet and easier to clean if needed, but might be extremely slippery once it gets covered in biofilm?

Flagstone is VERY slippery! The gravel on my pond bottom is easy & comfortable to walk on (I usually wear water shoes, but have waded around barefoot) The places where we have large flat rocks (top of the fish cave is one huge flat stone) I have to avoid because it's like walking on ice. Even when it doesn't *look* like it's got a coating of algae, it's slick!

 

[brokensword]

Flagstone will indeed get slippery, but I've seen people do it in rec ponds.

We grew up swimming in quarry ponds and natural lakes so we never worried a whole lot about what we were stepping on. When I get in my pond now I wear Crocs or water shoes - helps with any slip and slide issues. But I've walked barefoot on the gravel, too and it's so smooth it's really not an issue.

I always get a bit wary of sand - I wonder if you would end up stirring it up to the point that it would make things cloudy. But no experience there. I do remember when we would swim in lakes that had sandy bottoms, you didn't want to dig too deep in the and - it got stinky very fast.

Lisa; the kind of sand I'm referring to is coarse sand; it will stir but settle quickly. This is not like play sand sold at box stores but the kind masons use.

 

[Lisak1]

Ah... gotcha.

 

[GBBUDD]

Lisa; the kind of sand I'm referring to is coarse sand; it will stir but settle quickly. This is not like play sand sold at box stores but the kind masons use.

Course sand usually half the price of fine sand