Wetland Pond Under-gravel Filtration

[Clayton]

Good day all. I have been watching many videos on constructing ponds and wetlands prior to my construction of my pond. Here is what I would like to achieve... A 35' x 25' x 6' Eco-system pond with Under-gravel suction and Skimmer filtration pumped externally to an above ground Wetland filtration system that will then flow to Waterfalls. I want a 2-way valve to take 1/3 of the water from the bottom of the gravel section and 2/3 from the skimmer. This will take 2/3's of the most oxygenated water from the top of the pond and also 1/3 of the water from the bottom of the pond to mix as well as take the fish waste from the bottom and move it to the Wetland above the falls. On the bottom of the Wetland area above the falls I will have the "Agua Boxes" to slow down the water and let the heavier sediments sink to the bottom where I will have a couple of pipes with holes or slots to be able to suck via gravity, these heavier waste sediments, out to the lawn or garden via a Slide valve. I will have the proper sized rocks then slightly smaller cobble on top of the River Rock that will empty to the stream/falls for further oxygenation of the water. Plants will be dispersed through out the pond mainly in crevices and wetlands. See below diagram. Please let me know what anyone thinks. Thank you

 

[Alice_Bee]

I have done it, and I will tell you that the next year, that pond bottom didn't stink of anaerobic hydrogen sulfide, and I didn't even have a pump on the pvc most of the time, I had a pvc framework under windowscreen (not aluminum - the other stuff) and plastic hardware cloth. However cleaning the undergravel filter on a pond is a lot more tricky than an aquarium. We ended up taking the ug out

I like your plan for pumping the under stuff up to the wetland. However, bottom drains can leak, so I usually don't use them. Done well, this could work.

 

[bagsmom]

Once you start talking plumbing and start using fractions, I am lost! LOL. I can't help with any of it, but it sounds neat!
I used to keep aquariums and loved under gravel filtration. I'm not sure, but I'm guessing as with any system, it will work better and there will be less to clean and maintain if you control the fish load. The more and larger fish you have, the harder your system will have to work. I can't wait to see your project take shape!

 

[poconojoe]

I'm not exactly sure of your description. Sounds like you have some great ideas. It's good that you are planning things out ahead of time.

There's a ton of information on this site, so go ahead and look around for any help you might need.

A lot of people use bog filtration, I'm not sure if that's what you are describing as a wetland. They have a 12" or so deep area sized at 30% of the ponds surface. The perforated or slotted pvc pipes are layed on the liner, then covered with 3/8" pea gravel. Pond water gets pumped into those pipes. The gravel get planted with all sorts of plants. There's a low spot or waterfall that allows the water to return to the pond.

I would also suggest you check out what is called a negative edge. I think it's a better choice than using a skimmer. Skimmers can get clogged, fish can get sucked into them and you have to make sure they are sealed properly to the liner.
So, look around...

 

[bagsmom]

Another alternative to a skimmer is an intake bay. I've noticed many pond builders doing this lately. I'm going to try it on my new pond, but so far, I've only dug 3/4 of the hole, so I can't share any experiences with using one just yet.

 

[GBBUDD]

I can relate with the undergravel system but i would not do the traditional pipe on the bottom of the pond and a grid then burried in gravel. I have been looking at the snorkel and centipede. dig a trench before the liner is installed and after the line is installed place the centipede in the trench then place stone around and over he centipede. that way the lowest part of the pond is the trench with a sucktion tube. eventually all sediment will make its way to the trench. the snorkel can then be run up the side to the surface and not have a penitration through the rubber that so many are afraid of. .

How to you plan on stabilizing the sides with 6' deep?

I hope you have a lot of friends thats going to be one heavy piece of rubber.

 

[GBBUDD]

I prefer a negative edge over a intake bay more work but larger rewards.

 

[Clayton]

All, great ideas. I have been trying to get away from the Aquascape way of their intake bay and their Snorkel/Centipede system. I've seen them doing that and I don't know that I totally agree with the idea. To me, waste material can get into the crevices of the Intake bay, break down, and eventually clog up the bay resulting in having to dismantle it at some future point to redo it. It also requires quite a patch of dedicated ground at pond level. That is why I want to place the Bog/Wetland above ground. The Bog/wetland is above the level of the pond so that I can use gravity to drain the sediments instead of having to buy a Sump Pump to try to clean it via Snorkel/Centipede. Also, I watched intently of a certain Professionals skimmer, (hint -DNA), that I have seen from his website and a video from his channel, and I pretty much copied it. The small amount of time spent briefly cleaning it out and the beneficial bacterial in it I see is a bonus. This way I should be able to take care of the debris that is floating on the pond as well as utilizing the fish waste and flushing the system. My worry is that I may not have the proper amount of O2 and circulation completely figured out. I've been in the planning stages of this for about 10 years and expect to be pulling the trigger within the next year.

 

[Clayton]

I prefer a negative edge over a intake bay more work but larger rewards.

I will check this out

 

[Clayton]

I can relate with the undergravel system but i would not do the traditional pipe on the bottom of the pond and a grid then burried in gravel. I have been looking at the snorkel and centipede. dig a trench before the liner is installed and after the line is installed place the centipede in the trench then place stone around and over he centipede. that way the lowest part of the pond is the trench with a sucktion tube. eventually all sediment will make its way to the trench. the snorkel can then be run up the side to the surface and not have a penitration through the rubber that so many are afraid of. .

How to you plan on stabilizing the sides with 6' deep?

I hope you have a lot of friends thats going to be one heavy piece of rubber.

The pond will be terraced down to the 6' level not straight sides.

 

[poconojoe]

Another alternative to a skimmer is an intake bay. I've noticed many pond builders doing this lately. I'm going to try it on my new pond, but so far, I've only dug 3/4 of the hole, so I can't share any experiences with using one just yet.

Intake bay, negative edge, I don't know now... are they the same thing? Maybe when I suggested negative edge I meant intake bay? Now I'm confused and I don't want to misguide the OP.
So, what are the differences?

 

[GBBUDD]

 

[GBBUDD]

advatage to negative edge is the debris that gets into the negative edge is done i can not get back into the pond. Negative if it is not done right and the water is allowed to be to thick /tall a fish can swim over the edge and get into trouble. one way to fix is to make a small pool on the drop side of the negative edge.

Intake bay fish can swim in and out and never be in danger.. disadvantage so can all the debris that got pulled in a stong wind could blow it back into the pond.

 

[JBtheExplorer]

I'm really interested in seeing how this pond turns out! Good luck!

 

[GBBUDD]

Instead of all your pipes i would have the bottom like a funnel not flat but everything pitched toward the center or trench.

Is this to be a swim pond?