Can water critters keep my gravel beds from clogging up?

[Boscovius]

I'm actually planning a natural swimming pool with an upflow style bog filter area. I have heard of situations whereby downward fed bog filters with membranes can get clogged up. I was planning on forgoing any such membrane and use an upflow gravel bed, using increasingly smaller stone as I move upwards to the surface layer, where it would be mostly pea gravel. I was hoping someone might have some information about how beneficial creatures might be able to inhabit the gravel bed ,without being a hindrance to the enjoyment of the pool itself, of course.

 

[j.w]

@Boscovius

 

[GBBUDD]

It takes time to get to that point your talking about . first is the bacteria, then you'll get the micro organisms and the beetles , worms and bugs

 

[Lisak1]

I had to read your post twice to understand - you're just talking about the gravel style bog filter that most of us have on our ponds, correct? If your water is being pushed upward through the gravel, why are you concerned it would get clogged? The water you send to your filter should be clear and free of debris.

 

[Beercan31]

as I see it, it's not a direct A,B,C answer. Like @GBBUDD stated it takes time for a bio filter to come on line or aka cycle. it also depends on temperature, load and flow rate.

If it's a up flow filter once it cycles as bugs and bacteria do their job and the flow rate is correct for it's size the waste will settle out and fall to the bottom. So all in all you are less likely to clog your system if you all the parameters are correct.

 

[GBBUDD]

In time even with debris clear water the fine fish waste will start to accumulate and when it does water rakes the path of least resistance so in one area as the fines build up so much it can clog an area but then comes the magic . Pressure builds and another area gets fluhed and allows the flow at that spot allowing the micro organisms time to get to the clog and eat it upbuild there tunnels have their babies and multiply . To the point they weaken the gloged area and the pressure shifts to that area again and opens the flow . So on and so on.

 

[GBBUDD]

The weir as it drops out is the most common area for water loss. You have your flange cut around it but how far out does Containment go from those edges and is it higher than the weir.

From the picture I suspect not.
Water erosion / is streams cuyt there way into the landscape . If your weir is amoungest the highest areas it's very difficult to control the water. The liner should extend at least a foot to each side. Even if you can see the water is controlled now weeks months or even years from now that can change with a single lease or even some moss growing diverting the water.

 

[Jhn]

What beneficial creatures are you looking to inhabit the gravel bed, below and above water? above and below water those creatures will just show up, below the waterline freshwater is much more limited than a saltwater system in variety of beneficial creatures, as you are going to be limited by your gravel size being to large for any variety of underwater fauna and they aren’t really going to be stirring anything per se, the only truly beneficial underwater macrofauna creature you could add that would benefit the whole system imo, would be the gammarus shrimp, that may inhabit the gravel bed.

Really if you get your flow rate right so it slows as it enters the bottom of the bog so any sediment/fines will fall out as it enters then accelerates as it rises through the graduated gravel layers, and plant it correctly ie no plants that have extensive deep root systems the rest will pretty much take care of itself and you shouldn’t have any issues with clogging.

 

[Boscovius]

Thank you all for the helpful information. I have heard it argued that having fish in the water contributes to the development of algae in the pool, so I had planned on not having fish in the pool. However, I have to wonder about the wisdom of this, as having small minnows eating algae and adding it's nutrient value to their body mass will suspend some of the biomass. Then, as birds and other wildlife occasionally pluck them from the shallows, their nutrients will be subtracted from the whole. I guess the jury is still out on that. As far as backpressure keeping the channels clear, I would only be using an airlift pump, but even so, there should be a certain amount of back pressure equal to the lifting force of the water column used for the lift. So it sounds like what I was imagining could take place, would take place, and that organisms, even micro-organisms, will inhabit the spaces between the gravel bed and consume whatever organic matter there is to consume. Probably my biggest take-away here is that I should plan and build a suitable area for any sediments to settle or filter out of the airlift/bubble pump so as not to introduce them to the gravel bed to begin with.

 

[Lisak1]

filter out of the airlift/bubble pump so as not to introduce them to the gravel bed to begin with.

That's the key in my mind. Will fine sediment still make it to the bog - yes. But you'll never even know it's there if your system is functioning properly. You just need to set your intentions realistically - natural swim pond, not crystal clear swimming pool.

 

[bagsmom]

You can also plan for some kind of clean-out in your construction! From everything I've read on here, a properly constructed system will work really well - and clogging shouldn't be much of an issue. My up flow bog filter is too new to know how it will ultimately function, but so far, so good!!!! I did come up with a sort of hybrid set up if the time comes that I need to flush it out. I have a way to shoot water out the end of the pipe that feeds the water into the bottom of the bog. I also have a snorkel access point where I can drop in a small submersible pump and suck out any accumulated muck. In the planning stages, it's easy to set up this kind of thing. Much harder to do later, after the pond is up and running.

 

[Bluerooster]

I have a natural swimming pond with an up flow bog filter. 90% of the time it's crystal clear, the rest of the time it's too dang cold to use it anyway. I've had some trouble with my bog (of my own making) last year. It seems that some of the plants have a deep root system that stop up the plumbing from time to time. I'll be removing those in a month or two when it warms up enough to get in there.
But still, it's not that big of a problem. I do vacuum it from time to time, and it goes through a sand filter when I do. Other than that, it's only the bog.

Bog at full rip this past July

and just another flower in the bog pic:

 

[Boscovius]

Bluerooster. Thank you for that. Very nice pool you have there!