I did see one on Amazon the other day and it was more like a mesh bag so it might even let roots go through it. I'm not sure it would do anything specific for particles though.
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@nshapiro also pointed out that it would be easier to break your pump by flooding it if you used it in the usual "push" mode. Just so I understand, is that a consideration /against/ modifying the pump?
@Odie91that's a great question and one that many people ask. I'm concerned that if we don't reverse the diaphragm we might risk suspending dust from the growth medium in the air (the pump has a small filter in it so sucked air would reduce that risk). But there are many reasons why you might want to let it stay as a pump: 1) it is safer to water (no risk of sucking water into the pump and ruining it if its pumping air out) and 2) you can pull more HCHO into the system if you have a pump on the ground while the plant is in the window as HCHO is heavier than air.
In this build, we didn't see an instruction to reverse the pump, so we worried about the hose going underwater and making bubbles. Is that a big problem? Like, is it a problem if it bubbles through the water before entering the root area? Someone said it could create carbonic acid, but doing this is pretty normal in a fishtank with plants, so... we weren't sure.
Of course this would make a difference if the pump were sucking from the hose:
Actually i wondered re: @nshapiro's note on might risk suspending dust from the growth medium in the air if, and this is weird, but putting a filter over the plant container top could help at all? Like, some plants grow through an X cut in a fabric sheet. I just wondered about if putting such a cover would reduce the risk of growth medium dust getting blown around.
In general, I'd think the dust might get tamped down by the water, thinking of how construction sites sometimes spray water to tamp down the dust. But not sure - maybe that's pretty cursory and doesn't even work well.