Blue eco Upgrade at PSKoi

[Russell Peters]

The filter chamber is 4' x 9'6" and is fed by these two 4" lines.

[Russell Peters]

Today the sun was out and we had clear skies. It is so much nicer not to have to work in the mud. All of the rebar for the perimeter of the pond and the floor was completed today and I got some blocking in where the 4" pipes exit the pond.

[Russell Peters]

I was going to wait until Saturday to start with the inner forms but we had about an hour left in the day so I decided to hang the forms for one of the side walls. When I started with the outer forms I picked a depth that would allow for full 2 x 12 form boards without having to rip them down of put in a different size. The depth of the whole pond is equal to 6 - 2 x 12 boards and another 8" for concrete. Notice that the bottom of the form is not being supported from the bottom...yet.

[Russell Peters]

The end of the sidewall form is where the water in the pond stops and where the forms for the filter chamber start. The inside dimension for the filter chamber, short side, is 4' so I need 5' 1/8" of distance for the forms of the filter chamber. Each form board is 1-9/16" thick, need two of those, and then 4' for water.

[Russell Peters]

Today was day 5 and the pond is just about ready for the pour. I could have finished to forms today but I decided to work on getting the drainage system in place for the pond instead. On one of the 4" lines feeding the biological filter basin I put in a 4 x 3 wye so that it could be drained out without the possibility of draining out the pond. With this system the pond level could never fall more than 29" but the filter pit could be emptied down to 8" from the bottom.

[Russell Peters]

I put in a double 3" wye that would allow me to connect another pond to the same drainage system. That pond will be the mirror image of this one. The double wye is just after the gate valve. You can see three other 3" pipes rising up just after the double wye as well. The first one will be for the drain on the Blue eco RDF for this pond, the second one is for the drainage on the Blue Eco RDF for the next pond and the third one is for and area drain in between the two ponds. I will alter these 3 pipes when the time comes but I just wanted them stubbed up for the time being. The 2" white pipe is for the pressurized drainage system I have for my other tanks.

[Russell Peters]

The inside forms of the pond are complete, except for the bracing, and most of the inside forms on the filter pit are complete.

[Russell Peters]

When I do builds like these I always start out by setting a single layer of the outside form on the ground. I do this because it outlines exactly where the dig should be and keeps any over digging from happening. Once the form board is set I install what I call 'outriggers' on the perimeter of the forms. This is a triangular shaped wood structure that extends out 2' from the form and 3' up the side of the form. Once attached it keeps the outer forms in place. The digging goes straight down from the inside face of the forms and, if the outriggers weren't there, the forms could actually sink into the ground, or even worse, they could collapse into the dig.
Once the outer forms are complete, the plumbing and rebar are in place, I then put some 2 x 12's across the top of the outer forms so that I have something to support the inner form walls as I build them. Once they are braced, and supported by metal stakes, I then remove the 2 x 12's.
In the picture I have circled two of the outriggers and you can see two of the 2 x 12's across the top of the forms.

[Russell Peters]

The reason I am posting this is that we had a lot of rain for the fist time in almost a year. The ground was fairly soft to start with and the outriggers did hold the outer forms beautifully. When I removed the 2 x 12's, after completing the inner forms on Sunday, the inner forms began to sink into the ground. They had sunk 2" before I noticed it. This was because of the rain and the already very soft ground. As a general contractor who worked in S.F. for 20 years I had to deal with a lot of very old homes and, because of this, I have some very powerful jacks. I used the jacks when replacing foundations under homes. I got out one of my smaller 12 ton jacks, put several 2 x 12's back on top of the forms, and began lifting the inner forms one corner at a time. I then used 3" screws and attached the inner forms to the 2 x 12's with a total of 18 screws. It worked but wasn't perfect as the inner forms had shifted a bit and the weight of the inner forms was slowly bending the 2 x 12's. By the time we poured the inner forms were down about 1/4" but, with other issues, we had to determine at what new level the top of the pond should be. I had my concrete finishers finish the top down a bit from the outside edge to keep everything as even as possible. The concrete pour could not come soon enough.

The first nine yards of the pour went in without issue and the forms did not move. When the second truck of concrete arrived the driver pressurized his water supply but didn't realize the valve to the concrete was open. So, while he was getting my signature on the delivery papers, the concrete in the truck was turning into soup. We could not use the concrete so we had to reject it and wait 1 1/2 hours for another load to be delivered. It was getting late but the top of the first pour was still soft so there was no issue. The issue was time. We started the pour at 8am and it should have been done by 10am. It was now noon. When we requested the new concrete we asked for 2% calcium to speed up the set time so my finishers would not have to be finishing at 8pm. It worked very well and they were done by 3pm.

The 2 x 4 on the bottom drain, to the side wall, was how my finishers finished the floor and then got out.

[Russell Peters]

It has been a while since I posted updates and it is because of all the rain. I am roughly 9 working days into this now and it is very close to getting filled, although I won't do that until I get back from Japan. I was lucky in that I did not need to spend most of a day making sure everything was level, I think I spent about two hours on that.

This picture shows the grates on the bottom of the filter chamber. From the top of the wall to the top of the grates is 5'2"