Questions regarding cleaning out pond and building bog

[addy1]

Remind me, are you putting a liner over the blocks or will the wall be just to keep the pea gravel out of the pond and the water will weep through it?

 

[Karin]

the wall is just to keep the pea gravel in place and the water will weep through it.

 

[addy1]

the wall is just to keep the pea gravel in place and the water will weep through it.

There are different feelings about concrete blocks in the pond. They can change the ph, I have had some in my small hot tub pond without issue. But that many might cause a ph issue, the blocks have lime in them.
I made my wall out of landscape timbers, it is covered with liner.

The other thing, I would make sure to add some support, IMHO . You will have water pushing on the one side, gravel and water pushing on the other side. It would be a real pita if the wall collapsed.

It would be great if you could get some nice big flat rocks, but they can be pricey. Here called pa field stone.

 

[Karin]

Wow. I had thought these heavy concrete blocks would work better than the stone because I could build it more "watertight." I almost considered closing the gaps with that expandable stuff used for waterfalls. So, I have all kinds of rocks in my yard (but they are mostly limestone). Would those be an issue?

 

[addy1]

Well if you are building a barrier wall, ie the water will weep through, you don't want to make the wall water tight. You want to have it tight enough the pea gravels stays were it belongs, but the water can weep through. Over time most of the water will flow up and over the wall as the small gaps fill with dirt etc.

So make sure your wall is lower that the bogs liner edge.

I really don't know about lime stone rocks, we have quartz or shale in my yard. I did buy large boulders and a pallet of flat field stone when working on my ponds.

 

[addy1]

Per the net

"People actually add limestone to ponds to raise the ph. Koi and goldfish prefer high ph between 7.0 and 8.6. The maximum level that limestone can alter water is 8.3 . "

 

[addy1]

Here is a different opinion

Limestone gravel is not my first choice. The pond water will slowly dissolve the limestone gravel. If the water being used in the pond is not normally hard the limestone will make it that way. My own pond I used Limestone gravel 3/4 to 1″ round. The hardness of the water used for the pond is 450 ppm so the gravel didn't change it.

 

[Karin]

ok, that sound like a good plan. We have a wonderful store called "House of Rock"that sells all kinds of stone. I can always use the concrete blocks for making something else..... thank you so much! I am learning a lot! This 2 day project just seems to have a few "kinks" that are slowing me down a lot. One other question, the 2" pvc pipe I am running through the bog will be 10 ft long (5' and 5' lengths joined by a 45 degree elbow so it can follow the curve of the pond. I will attach the pump hose to one end and the cleanout pipe to the other end. Is that considered a long run? Should I be making the slits in the PVC 1" apart or wider?

 

[GBBUDD]

I really don't know about lime stone rocks, we have quartz or shale in my yard. I did buy large boulders and a pallet of flat field stone when working on my ponds.

Considering weathered lime stone is the go to for most of the Aquasape pond builds i would have to say there is no issue but possibly a true benefit to using lime stone i would think it would help soften the water and it would only leach very slowly

 

[Karin]

okay, I can use whatever limestone I have and then finish with fieldstone. I don't think I will have enough of the limestone to build the entire bog wall.

 

[addy1]

Should I be making the slits in the PVC 1" apart or wider?

My slits are around 6 inches apart. You are mainly trying to make sure water flows through a lot of the gravel. I placed my slits down and put some scrap liner under the pipes so the water would not be pounding on the main liner for years.

 

[Karin]

I finally finished building my bog wall and have most of 3 tons of gravel in it. I started planting it already, too, because the fish are in a holding tank (very nice, with filter and plants) but I am anxious to get them into the pond, so I need my plant filters. Here is why this build has taken so long: I had a ton of pea gravel that had been in the pond, which I washed, but it was only enough to just cover the pipe. The 2 tons of pea gravel that I had delivered was super dirty with lots and lots of little tiny pieces of gravel and sandy bits- less than an 1/8" of an inch, so I got a 1/4" hardware screen and sieved the gravel while washing it. I also "unburied the pipe and wrapped it with fiberglass screen and tied it in place every 3" with zipties, just to be on the safe side. Two days ago, I thought I was almost done - I had 8" of water and gravel in the bog. I turned the pump on and water was flowing nicely into and out of the bog. But the next morning the water level in the pond had dropped a lot. It was about 2 inches below a 4" deep shelf which was now exposed. I didn't want that, and if I left it that way the water level in the bog would be only 8" deep. So I wanted to fix the leak. I read a lot about fixing leaks and then started to work. First I had to peel back the geotextile that I have on top of the liner. I didn't find the leak checking the with my fingers. I added water to an inch above the leak and then through in some condensed milk to see if I could find where the leak was exactly. The milk just floated and slowly diffused. I was tired and went to bed thinking I would try again in the morning. The next morning, my husband told me I better check the pond, there was something strange going on... I looked at it and the water was covering the shelf by about an inch. So there was no leak! My thought is that the pump must be pumping water into the bog faster than it is draining. Since the pump was off overnight, all the water that had been in the bog seeped back into the pond. I checked the liner again on the bog side and made sure it was much higher, just in case. I should probably turn down the pump, too. Here are some photos: 1 & 2 Dirty gravel and the pile of "fines"....
3. happy fish in holding tank
4. Partially filled bog and pond. Yay!!

 

[poconojoe]

This might be a dumb question and I don't mean to insult you either...

Did you take in consideration that the bog is going to hold a significant amount of water?

If you didn't fill the bog with water first, your pump is going fill it with pond water. The level of your pond is going to drop which can give you a false impression that there is a leak.

 

[Karin]

This might be a dumb question and I don't mean to insult you either...

Did you take in consideration that the bog is going to hold a significant amount of water?

If you didn't fill the bog with water first, your pump is going fill it with pond water. The level of your pond is going to drop which can give you a false impression that there is a leak.

Yes, that is exactly right, and I did not! Since the bog is within the pond, I didn't think there would be a difference in water levels. And I bought a pump that is bigger than what I need for the size of my pond, which, I overestimated in gallons. But I tested the output of my hose after draining and cleaning my pond, and it holds only 830 gallons... That just seems crazy little, but I do have a lot of shallow borders. The pump is for 2300. I have been watching it like a hawk to make sure the bog liner is tall enough.

 

[poconojoe]

Yes, that is exactly right, and I did not! Since the bog is within the pond, I didn't think there would be a difference in water levels. And I bought a pump that is bigger than what I need for the size of my pond, which, I overestimated in gallons. But I tested the output of my hose after draining and cleaning my pond, and it holds only 830 gallons... That just seems crazy little, but I do have a lot of shallow borders. The pump is for 2300. I have been watching it like a hawk to make sure the bog liner is tall enough.

Ah, the bog is within the pond, so you figured the water level was equalized already, but when you turned the pump on the pond level lowered.
I get that!
Well, I'm so glad you didn't have a leak. That situation can be quite stressful.

I once had a branch puncture the bottom of a pond that had a crummy PVC liner and it was in the dead of winter. PVC is the worse liner, but I was a newbie and wasn't privy to that. I tried underwater patches, underwater sealants but nothing worked. Anyway, there was no way to replace that liner until it warmed up in the spring. I was adding 300 gallons every week until Spring.

Anyway, enjoy!