Conversion 30,000 gal Saltwater concrete-with-liner pool to garden pond

[GBBUDD]

I don't know how I didn't get fired!

Accidents happen...... but the average Olympic swimming pool is around 600,000 gallons

 

[GBBUDD]

adding 10,000 gallons

In my area 6,000 gallons brought by a tanker truck is $300

 

[jsam]

We recently had some warmer weather and my pond started turning much greener so we are building a bog that will be just under 20% of my pond area. It will be about 15 inches deep and will have a two tiered water fall with water coming from an underwater pump at the 9 foot deep end. We are building over the concrete pool apron because we are unsure of its depth and do not want to disrupt the pool liner at this time. Right now my water temperature is 42 degrees.
I tried to find recommendations for placement of the PVC pipes and placement of the holes but could not find anything that convinced me so asking for advice. I will have six 13 foot long (so about 6 feet on each side) 1 1/2 inch lateral pipes running off a 7 foot center pipe.
Questions are.
1. Do I cap the lateral pipes at each end or should I use t-pieces and have a continuous loop? I need the water to circulate all over the bog and I am concerned the loop will not have enough pressure in the far corners to filter out thru the holes.
2. I have seen recommendations to have the holes on the bottom and on the top of the PVC pipes and they both seem like good reasons or can I put holes all around or even just on the sides?

Description of pictures below.
The water fall is in the center and the smaller set back to the left will be for a large urn and the larger set back on the right will be for a cedar bench next to the water fall. Unfortunately we are waiting on material so we can not move forward, however we have another project at the other end of the pond. We have the hill that drained toward the pond and when it rained it became a mud slide. So we have put in flagstone stairs and working on a patio at the bottom to divert the water and have a place to sit and enjoy the waterfall from that end of the pond. These are our projects when the weather is nice and we still have a list of projects to do when the weather drives us inside.
As you can tell our backyard looks like a construction site though I am enjoying every minute of it (except at the end of the day.....when everything aches) and still really happy we converted the pool to a pond.

 

[brokensword]

We recently had some warmer weather and my pond started turning much greener so we are building a bog that will be just under 20% of my pond area. It will be about 15 inches deep and will have a two tiered water fall with water coming from an underwater pump at the 9 foot deep end. We are building over the concrete pool apron because we are unsure of its depth and do not want to disrupt the pool liner at this time. Right now my water temperature is 42 degrees.
I tried to find recommendations for placement of the PVC pipes and placement of the holes but could not find anything that convinced me so asking for advice. I will have six 13 foot long (so about 6 feet on each side) 1 1/2 inch lateral pipes running off a 7 foot center pipe.
Questions are.
1. Do I cap the lateral pipes at each end or should I use t-pieces and have a continuous loop? I need the water to circulate all over the bog and I am concerned the loop will not have enough pressure in the far corners to filter out thru the holes.
2. I have seen recommendations to have the holes on the bottom and on the top of the PVC pipes and they both seem like good reasons or can I put holes all around or even just on the sides?

Description of pictures below.
The water fall is in the center and the smaller set back to the left will be for a large urn and the larger set back on the right will be for a cedar bench next to the water fall. Unfortunately we are waiting on material so we can not move forward, however we have another project at the other end of the pond. We have the hill that drained toward the pond and when it rained it became a mud slide. So we have put in flagstone stairs and working on a patio at the bottom to divert the water and have a place to sit and enjoy the waterfall from that end of the pond. These are our projects when the weather is nice and we still have a list of projects to do when the weather drives us inside.
As you can tell our backyard looks like a construction site though I am enjoying every minute of it (except at the end of the day.....when everything aches) and still really happy we converted the pool to a pond.

An easy way to get around such issues is to create a 'dead space' below the pea gravel. You'll need to build your bog box 8" or so higher to accommodate. Some here will tell you spring for the Aquablox, I'll tell you you can get the same action with larger, round boulders in the 8" diameter arena. What I did was put one course of 8" boulders along side and over my bog manifolds. Then a 12" layer of 2" round cobblestone. Then lastly, a 12" layer of pea gravel. As you can see, the bog will be higher (that's why mine is in the ground) but doing something like this would be better for all your concerns.

If you want to clean/clear any manifold pipes, put vertical risers at each branch end such that they extend just above the final water line and use screw on caps. The other thought is if you want to ever backflush the whole bog, you create a vault and snorkel system. This is a wider pipe-like structure that goes top to bottom of your bog, something with a diameter large enough to get a secondary pump into it and as you force water back through from the top of your bog, the debris heads toward this cleanout where your second pump pumps it out. Those are two cleaning options.

I put my manifold 'slits' (not holes!) facing up as per a pond professional's advice. Personally, I think the water exits easier this way and since they're slits, no pea gravel is going to clog/get stuck inside). Too, I used 4" drain tile piping, not rigid sched 40 pvc as most do. So, I have a lot more volume for the water to exit than others and it'll be harder to clog, hence I don't have the risers, I only have a DIY snorkel and vault, for that (hopefully) rare occasion of backflushing.


And realize, you don't need so many manifolds/branches, though it won't hurt. Once the water gets out, IF you have this dead space, the water will find it's way up, even if you ONLY have the main tube running from one end to the other(I have 2 four inch manifolds right next to each other, this way).
Hope this helps!

 

[GBBUDD]

Going with the PEASTONE bog has many success stories. TO me the you have a great deal of water and may need to consider a larger volume of water go to the bog and a higher turn over " how many times an hour you turn over how many gallons." MNodern design aquascaping recommends up to 50 percent the size of the surface for a highly used rec pond. I have seen many numbers and it all depends in my eyes how often and who is wearing how much suntan lotion and how many fish will be in the pond. how many trees over hang the pond.

BUT TO ANSWER YOUR QUESTIONS
90% of bogs are built with a 2 inch PVC pipe in a baffle configuration the best way to obtain complete distribution across the bottom would be to elevated the gravel above the pipe but if you go that far then i would just go with the matrix bogs. What is the most common is to use the 2" pipe and have it be fed from a 3" line in other words the three inch is the body of an octopus and or candelabra and have many taps or legs of two inch pvc come off of the 3" . a 2 inch line without pressure is only good for about 4500 gph i would think you should be looking around 7 to 8000. and using the three inch will allow growth if need be. and you can tap into that with as many 2" as you need. "within reason"

I would call aquascapes in chicago Illinois . I have heard they are willing to help with solutions such as yours .

@jsam what is your configuration that your thinking of ? what's the size is the bog.
One option you may want to look into is doing a gravel filter at the bottom of your pool.

Ohio fish rescue has some monster fish in an old pond has perfectly clear water and was built by aquascapes i believe it was.. Any way you slice it though if a submersible is installed in a POOL i would make damn sure the electrical line and the pump can not be accessed by anyone in the pool. in other words electrical line is in a conduit pipe and the pump absolutely can not suck someone long hair in and hold them under. ETC

I am a firm believer in slits facing down and the pipe elevated up off the bottom by and inch a simple piece of concrete patio block or even a brick will do the job. jUST USE CARE WHEN DUMPING THE STONE IN ONCE THE STONE IS UNDER THE PIPE YOUR ALL SET a slit cut 1/3rd of the way through the pipe. THE SLITS CUT APPROXIMATELY EVERY 6 INCHES. easiest way to do that for ME was to tape a few pipes together and then cut across them with a circular saw it is in my blog.

iF YOU MAKE A CONFIGURATION LIKE THE OCTOPUS THEN EACH LEG SHOULD HAVE A RISER PIPE WITH A CLEAN OUT better to have it and not need it then need it and not have it. the end caped with a threaded end cap.

I would also think about over sizing your liner in a big way . They recommended is 30% for a koi pond of the surface area you want to try for 20 and you have 30000 gallons if your next try fails and you need to if you have the liner already folded up along the new bog you can try an extension to the side make it taller and add more stone without starting from scratch.
what are you doing to contain the bog concrete block wood timber digging a trench ?

Apparently the first design was not doing the job is it going to help the bog or it it being removed?