First pond attempt - 3500 gallons

[MTguy]

Hi all, I am getting ready for my first attempt at a pond and I think it is a pretty good size (although as soon as I'm done I'll wish it was bigger, right?). I am essentially building an upper and lower pond with a 20' stream between them. The pond wraps around my elevated deck and there is a seating area with fire pit on the North side of my pond. There should not be much pond area set in shaded areas. Also important is that I live in North Dakota so this pond will completely freeze each winter.

My design starts with a 10'x5.5'x3' max depth top pond with 2 biofalls. This doesn't seem like it gives me a lot of ledge space for added interest under water, but I could be wrong. One consideration I had for this and did not implement is an undergravel filtration mechanism. It doesn't seem necessary. I do want to incorporate just a few sacrificial gold fish in the upper pond. Other than that, the top is pretty simple... I think.


This will feed a 24" wide stream that is generally 2" deep but I want to include some pools that get to around 6". There is virtually no slope between the upper pond and the 2/3 of the stream bed, then the last 1/3 of the stream I have approximately a 2 1/2' drop. I can do some manipulation of that, but not a lot as I go over a pipe to my septic tank there (approximately where the brown dotted line in the diagram is). Another thing I would like to implement in the stream bed is a deeper gravel area where I can put a perforated PVC pipe to act as additional filtration. I'm not sure if I would need to push water into that PVC to gain any benefit or if the water will flow through enough without it? The reasons I want to do this are because the plants will hide the ugly area under my deck, added filtration is always good (I think), and because I have a 10' wide stream liner to work with anyway.

The bottom pond is a 13x7x3' max depth pond fed by the stream/waterfall. At the far end of the pond will be a skimmer to cycle the water back to the top. Overflow would be on the right side which is where my yard already takes it. I also have a gutter drain that normally discharges near the skimmer box which I'm thinking of routing towards the pond to keep it topped off. Maybe in the future I'll build some underground rainwater storage there as well/instead to keep the pond filled. I would probably keep a few sacrificial gold fish in the lower pond as well.

I do have the space and desire to add an additional waterfall area that would be coming from under my deck and provide me a small seating area to sit and enjoy the waterfalls on both sides. This entire area would be in the shade though. One of the questions I have right now is what the best/smart way to feed the new falls would be? I was considering putting in a perforated PVC grid on the bottom of the lower pond with a 2" outlet so that I can connect a future pump to act as a filter similar to what you would see in an aquarium. I'm not sure what the best way to build is now though to have that ready. If I go with an external pump, I would probably run my line now so I can hide it with rocks. If I were to implement a submerged pump I think I would just create a hidden space to stash the pump and line. For filtration for the future falls I think I would either just go with a pressure filter w/ UV or a simple filter box that gravity drains back.

My plans for equipment right now are as follows:
Biofalls (x2) = Aquascape 77020
Skimmer = Aquascape 43020
Pump = Alpine Pal 4000 which should hopefully be pushing 3,000 gph at 7 ft pump head
2" flex pipe into a 2" PVC manifold that scales down to 1.5" after the tees before the biofalls.
Pond liner is 45mil EPDM which will be seamed with 3" under tape and 6" over tape.
I'm estimating the need for 10 tons of boulders (10" to 28") and 4 tons of river rock.
Planning to use old carpet for liner pad.

That was a huge post. Any advice is greatly appreciated. Expecting to be a couple weeks out before I break ground. Thinking I can make it all happen for $2300 and a lot back breaking work!

 

[poconojoe]

When you say the pond will "completely freeze ", I don't think you actually meant it will freeze completely through from top to bottom. There will definitely be liquid water under a layer of ice. If you have fish, you should keep a small opening in the ice for gas exchange. A low wattage 250 watt deicer works well for that.

 

[MTguy]

I actually did /do believe it will freeze completely. The lake next to me gets 2’ of ice each winter so I assumed this would get more ice (without a de-icer). I wasn’t planning on doing anything with it over the winter. That’s why I was calling the fish sacrificial. If I added a de-icer should I also add aeration over the winter?

 

[poconojoe]

I'm in zone 6b. Northeastern PA. My altitude is about 2,000 feet. The ice on my pond gets around 6" to 8" thick.
I do both. Deicer and aeration. I have two large air stones running off my aerator. In the winter I have the air stones about 12" below the water surface. I don't want freezing cold air pumped into the bottom where the fish are hibernating. In the Summer, I drop them to the bottom.
I use a 250 watt deicer just to keep a hole open. I once had a 750 watt deicer and it was too powerful. It kept a big area of open water.

 

[MTguy]

I’m in zone 4a here. I’m not sure how my plants will fare, but I’m assuming they’ll be alright if I stick to plants that are native.

Does my equipment seem adequate for this setup? I don’t want to have to do it twice.

 

[sissy]

you may want to remember to protect your hoses that run from the pump to the other pond and stream .If a leak happens after you are done it could be a big problem ,plus the longer the hose is out of the water the less pressure you will get .I have a 5000 gallon pond with 2 filters and my hoses stay inside the pond so if there is ever a leak the water can only go back into the pond .I do not have a skimmer ,but have 2 homemade filter tanks and 2 pumps and a aerator and you will need to think about electrical use and how many outlets you want and have them on a dedicated breaker .When electric is put in more electric outlets the better as you never know what you may want in the future to plug in .Better to pay once .Mark out the area for the pond so you will know where to put your outlets .Right now i have 8 double outlets just for the pond and 3 for the front porch under it and under the steps .

 

[j.w]

@MTguy

 

[MTguy]

Thanks Sissy. My plan was to run them underground (which is under my wooden deck) straight to my waterfalls as that is the shortest distance. Do you recommend running a liner or something underneath it in the event of a leak?

For my electrical, right now I am only projecting one pump and led pond lighting. The pump I'm looking at is a 306 watts. For $10 more I can go up another 1200gph but that would put me at 426 watts, which would start to get expensive. I'm HOPING (and I realize that hope is not a strategy!) that one outlet (2 available plugs) will be enough to run what I've got for now. I do have one available circuit I can tie into if need be but I'd need to run about 100' of conduit and wire. That circuit could be either 120 or 240 volt though, so that's nice. In the winter, if I go with a de-icer and aeration I would unplug the pump and lighting so I one outlet should be enough for now.

 

[sissy]

If you have a basement that may flood or in your case it could freeze if it leaks and crack your foundation .I live in VA but still put water diverters under both of my decks to divert the water away from the foundation .My pond is down below my front covered porch and then my yard slopes down from there .We can get some really heavy rains here but very little snow and usually it only lasts a day or 2 .The foundation of a house is the most important part of the house .I have 2 laguna pumps and 1 is 2400 gph and the other is 2900 gph and my aerator is laguna .All 3 I tested on the watt tester an the 2 pumps run about 110 watts and the aerator uses 45 watts .I do not want a high electric bill .Plus if 1 pump goes out I am not in a panic .I live in a rural area .The extra water goes to pvc pipe that I added to my sump pump hose that goes to my pumps and filters and my waterfall spitter is pvc pipe .I drilled holes in it so that the water coming out aerates and moves water across the bottom of the pond to help keep it clean .you have to think outside the box with a pond

 

[MTguy]

Sissy, do you have a picture of your PVC waterfall splitter? I considered using one, but wasn’t sure how I’d make it work.

 

[MTguy]

I’m already considering a redesign.... instead of a skimmer I’m thinking I would be better off with a zero edge pump basin. I have a gutter right next to the area that I could use for rain catchment. I think this would also allow me to turn off the waterfall at night if I wanted. I’m struggling with a way to dondo it affordably and aesthetically pleasing. I am considering heavy duty milk crates instead of aqua blocks and a water meter box with risers for the pump basin. I think if I could do a 3’ deep by 6’x6’ area I could have around 600 gallons of storage. I’m just not sure how I will make the overflow work from there as I don’t really have anymore elevation to work with.

 

[addy1]

Think outside the pond box! I tend to do things see if they work, if not move on to something else. I have zero experience with aqua blocks, my system is just pea gravel, plants, water.

 

[sissy]

I think there may be a pic of it on my pond build .It is raining now so can't get a pic but it is just made of pvc and used sump pump hose and clamps

 

[MTguy]

Reworking the plan while I still have some time before breaking ground. My new plan is to do a zero edge collection basin so I can add some water storage/rainwater collection. What do you think about using these septic leach chambers instead of aquablocks? I am also thinking of using these sump pump basins with holes drilled in them instead of a pump vault. My new plan is to create an 11' x 6' x 2.5' deep basin that could fill up like an intake bay if the water level got high enough. I'm thinking of using 3 of the drain field chambers 1.5 chambers next to each other with a sump basin on the end of each row so I can have 2 pumps. If my calculations are correct I can have up to 1238 gallons of water in the area minus the rock volume. The cost would be approximately $40 more for the extra liner, $66 for the sump basins & lids, and $180 for the leaching chambers and ends. That totals out to $286 for all of it which is more than the $200 for a skimmer but much less than the $1,240 for aquablocks and their pump vaults.

Thoughts? By going to a larger liner and adding the zero edge basin I lose about 4' of pond length on the lower pond (unless the water level gets high enough to have an intake bay appearance). My guesstimate is that adding the extra area for water storage and pump basins plus some initial filtration I'll be better off than using a skimmer as far as maintenance/cost of operation. I'm not sure how I weight that against the loss of visible pond area though.
*Edit: I plan to put about 6" of gravel on top of the chambers. The manufacturer states that 12" of compacted soil on top will support a 16 ton axle driving over it (although they say don't drive on it). I don't plan to put plants in the intake area either due to concerns it would clog the chambers.

 

[MTguy]

And another thing.... I was considering swapping out the two biofalls for a 100 gallon skippy filter with two outlets. The whole thing will be hidden under my deck anyway, so I thought I could get more filtration for about the same price. I would just use a 110 gallon stock tank/tub, bulkheads and cut to size filter mats. I would also likely end up with some bio-balls in there as well.