Rocks on the bottom?


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I was just thinking if you built a grid water collection on the bottom of the pond like an under gravel system. Placed in larger rocks 2"-6"ish and then fed to your filter system would this stop the buildup problems in the bottom that you get with rocks on the bottom. You would also not have the cleanup that you get with an under gravel system.
Like the looks of the rock bottom but it does create a problem with fish waste.
 
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I see what you're thinking here, but my question would be how would you make sure the debris doesn't just settle under your grid? You'd need to have a way to keep the water moving under the grid. I'm assuming you'd use a bottom drain?
 
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You could run water into grid instead of pull. If you study further you will find the rocked bottom being a bad thing kind of out dated. Although if you want true koi pond and its deep the rocked bottom kind of a moot point. In my current shallow pond I look at the rocks as another biological filtering.
 
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you will find the rocked bottom being a bad thing kind of out dated.
You do have to be careful to make sure you're talking about the same thing. A GRAVEL bottom is a good thing; a ROCK bottom can be troublesome. The difference being gravel is easily stirred up and shallow so the detritus doesn't have a chance to build up. If you have larger rocks in the bottom they tend to just sit in one place and the spaces between can become filled with decaying debris.
 
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I see what you're thinking here, but my question would be how would you make sure the debris doesn't just settle under your grid? You'd need to have a way to keep the water moving under the grid. I'm assuming you'd use a bottom drain?
I think a setup similar to my bottom drain would work for this where you would have the water sucked out from the designated area and fed to a filter or skimmer. Somewhat like an undergravel filter system in an aquarium.
 
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Yes and no - the bottom drain does draw water, but how far? I would assume a grid with rocks on top would limit any water motion from the waterfall, so you would have no current in the pond other than that created by the draw from the bottom drain, right? Would that be enough to sweep the whole floor of the pond?
 
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Yes and no - the bottom drain does draw water, but how far? I would assume a grid with rocks on top would limit any water motion from the waterfall, so you would have no current in the pond other than that created by the draw from the bottom drain, right? Would that be enough to sweep the whole floor of the pond?
Bottom Drain set ups also include strategically placed tpr's to increase water flow towards the bottom drain. The sweep area of the bottom drain is dependent on the the size of the pipes . I would think rocks and even gravel would reduce the flow towards the drain by adding resistance
 
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I would think rocks and even gravel would reduce the flow towards the drain by adding resistance
I think the idea posed was a grid that would hold the rocks up above the pond bottom. The water under the grid would be free of rocks or gravel.

I'm guessing a TPR is a jet?
 
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Yes and no - the bottom drain does draw water, but how far? I would assume a grid with rocks on top would limit any water motion from the waterfall, so you would have no current in the pond other than that created by the draw from the bottom drain, right? Would that be enough to sweep the whole floor of the pond?
I think it could be depending on the power of the pump used and the design of the underground grid. Some what like a large thin aquablox grid under the rock where debris could slip through it and be sucked away via a strong pump.
 
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I think the idea posed was a grid that would hold the rocks up above the pond bottom. The water under the grid would be free of rocks or gravel.

I'm guessing a TPR is a jet?
Yes. So if the rocks are sitting on top of the grid them the grid is on the pond floor creating the same restriction and places for gunk to get trapped and collect.
 
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Yes. So if the rocks are sitting on top of the grid them the grid is on the pond floor creating the same restriction and places for gunk to get trapped and collect.
Ah! Gotcha! Good point. You'd still have the same issue as if the rocks were directly on the pond floor.
 

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