DIY swimming pool/pond?

[Mgmny]

Hello!

I have a small (1500 gallon) fish pond in my backyard and a stream in my backyard. After some thinking (and the recent trend of natural swimming pond/pool), I was wondering if i can create a natural (or chlorinated, i don't need plants) swimming pool easily in my backyard.

In my mind: Dig a hole that slopes down gradually to maybe 5' deep x 12' across and maybe 20' long - so not huge. Use black pond liner to waterproof the hole. Add large rocks/boulders INSIDE the pool (on top of the pond liner) to support the walls and add interest. Heck, the whole bottom could be rocks. At the deep end of the pool, I would have a waterfall feature that pumps water from the bottom of the pool through a filter, to a upper, smaller pool that would cascade/fall into the main basin.

Concerns:

I imagine i'll need a LOT of rocks/boulders along the end of the pool so the edges don't collapse - i've seen diy pools use retaining wall blocks for this, but those people are also  putting a beautiful pool liner and straight wall - i am OK with the more natural/slopped look of the walls.

A lot of websites i read about talk about circulation "dead zones" as a concern. Does this honestly matter? If I chlorinate the water, algae shouldn't grow anyways, right? So why do I really care about circulation dead zones? With the waterfall, I would imagine the water would turn over fairly frequently? I don't plan on putting wall jets in (not sure how i would diy that anyways), but 2 pipes (one for each side of the pool) going to 2 pumps, through a filter, and to the waterfall pool that would spill into the main pool.

Will chlorinated water discolor/bleach natural stone?If so, that would be a deal-breaker probably.



Closing thoughts: This is probably a crazy thought, and the fact that other people don't do this makes me think it's not a viable option. Maybe it would turn out ugly, or gross. So please, tell me why this idea won't work. Depending on excavation methods, cost of rocks, i would honestly think i can do this for $1-2k - compared to the >$10k for a "normal" swimming pool.

[Mgmny]

In  my mind, it would look like this (but on a much smaller scale)

[Spork]

My concern (without thinking much) is that black pond liner would make an unbearably hot pool.

I do think it is possible to build a liner pond yourself.  My cousin did it.  It's not rocket science.  If you want it perfectly square with a slope that is perfect from the deep to shallow end... that's hard.   If you want something natural looking.... probably still difficult, but I bet it's do-able.  Getting all the wrinkles out of the liner with a nice bottom that is visually appealing seems like the hard part.

[Mgmny]

My concern (without thinking much) is that black pond liner would make an unbearably hot pool.

I do think it is possible to build a liner pond yourself.  My cousin did it.  It's not rocket science.  If you want it perfectly square with a slope that is perfect from the deep to shallow end... that's hard.   If you want something natural looking.... probably still difficult, but I bet it's do-able.  Getting all the wrinkles out of the liner with a nice bottom that is visually appealing seems like the hard part.

I live in Minnesota, so I'm not sure that it could be "unbearably hot" here, and maybe a welcome problem to have.

I hear you about the square and slope - I'm thinking adding rocks to it would mitigate some desire/need for perfect measurements.

[lthenderson]

I think it is possible but not with the dimensions you described. Five feet deep by 12 feet across means a 40 degree slope. I don't think you could stabilize that with rocks unless you took up most of the swimming space with rocks. I think it would have to be a much shallower slope. For a 20 degree slope, it would have to be 28 feet in diameter to achieve a 5 foot deep pool, not counting rocks that will take up some of that space later.

[Spork]

Just curious, since I've never seen them built... how does a liner pool normally stabilize the almost-vertical sides?   Is there some thick sheet of plastic behind the liner?  Or just sand (with water pressure holding it in place)?  I know the bottom is normally just sand under the liner, but have no clue about the sides.

I do know the liners do have to be replaced every 10-15 years.  Sister-in-law replaced hers 4-5 years ago.  (She did not do DIY, for what it's worth.)

[Mgmny]

Just curious, since I've never seen them built... how does a liner pool normally stabilize the almost-vertical sides?   Is there some thick sheet of plastic behind the liner?  Or just sand (with water pressure holding it in place)?  I know the bottom is normally just sand under the liner, but have no clue about the sides.

I do know the liners do have to be replaced every 10-15 years.  Sister-in-law replaced hers 4-5 years ago.  (She did not do DIY, for what it's worth.)

My grandparents-in-law have a normal swimming pool and i'm reasonably certain that he said there is sheet metal behind the pool liner. In Minnesota, some/most (not sure) drain part of their pools before winter to not crack the concrete on top.

[Mgmny]

I think it is possible but not with the dimensions you described. Five feet deep by 12 feet across means a 40 degree slope. I don't think you could stabilize that with rocks unless you took up most of the swimming space with rocks. I think it would have to be a much shallower slope. For a 20 degree slope, it would have to be 28 feet in diameter to achieve a 5 foot deep pool, not counting rocks that will take up some of that space later.

I meant 12 feet across and 20 feet from shallow to deep. That said, it looks like that isn't quite enough either. Maybe I don't need 5' deep? I wonder at what depth the average person starts floating?

[lthenderson]

I think it is possible but not with the dimensions you described. Five feet deep by 12 feet across means a 40 degree slope. I don't think you could stabilize that with rocks unless you took up most of the swimming space with rocks. I think it would have to be a much shallower slope. For a 20 degree slope, it would have to be 28 feet in diameter to achieve a 5 foot deep pool, not counting rocks that will take up some of that space later.

I meant 12 feet across and 20 feet from shallow to deep. That said, it looks like that isn't quite enough either. Maybe I don't need 5' deep? I wonder at what depth the average person starts floating?

We are on the same page. 12 feet across means 6 feet horizontal movement (from one edge to center) and 5 feet of vertical movement. That equals a 40 degree slope on the sides. Pretty steep for supporting five feet of earth long term with some "rocks".

I would want at least five feet deep so that I could stand on bottom and be submerged up to my neck. Four feet you either have to crouch all the time or stand with arms and shoulders out of the water. Technically one could float in less than a foot of water though.

[BudgetSlasher]

If you are going to go messing with an existing pond and stream, I would check with you state DEP/EPA to see if it is even allowable. You wouldn't want to find yourself on the wrong end of an enforcement case.

Also, I have read about swimming holes being made using a clay (bentonite I think) as a liner to hold in natural waters.

[Mgmny]

If you are going to go messing with an existing pond and stream, I would check with you state DEP/EPA to see if it is even allowable. You wouldn't want to find yourself on the wrong end of an enforcement case.

Also, I have read about swimming holes being made using a clay (bentonite I think) as a liner to hold in natural waters.

Thanks for looking out for me. I'll look into Bentonite!

The pond and stream are totally man made and reasonably small.

Here's the stream:

[Mgmny]

I think it is possible but not with the dimensions you described. Five feet deep by 12 feet across means a 40 degree slope. I don't think you could stabilize that with rocks unless you took up most of the swimming space with rocks. I think it would have to be a much shallower slope. For a 20 degree slope, it would have to be 28 feet in diameter to achieve a 5 foot deep pool, not counting rocks that will take up some of that space later.

I meant 12 feet across and 20 feet from shallow to deep. That said, it looks like that isn't quite enough either. Maybe I don't need 5' deep? I wonder at what depth the average person starts floating?

We are on the same page. 12 feet across means 6 feet horizontal movement (from one edge to center) and 5 feet of vertical movement. That equals a 40 degree slope on the sides. Pretty steep for supporting five feet of earth long term with some "rocks".

I would want at least five feet deep so that I could stand on bottom and be submerged up to my neck. Four feet you either have to crouch all the time or stand with arms and shoulders out of the water. Technically one could float in less than a foot of water though.

Good points.

So i wrote up a thing about how i don't think it's 40 degrees, I did the math, but now i realize that  you mean from the EDGES of the pool in the deep end of the pool. I was only thinking from shallow end of the 20' length to deep end of the 20' length. You also might be assuming the deep end is in the dead middle of the pool (and it could be - just not how i initially envisioned it).

I'm sorry, I completely spaced the fact that the ends of the pool need to slope to the deep part as well.

[RyanAtTanagra]

Posting to follow.  I like this idea and think it could be a really fun and rewarding project.  Have you made an progress on planning?

[Hadilly]

If you search for "Natural Swimming Pools" a lot of neat results come up. I would totally make one! Check out this DIY from Mother Earth News. Cool project!

Edited to add the link: http://www.motherearthnews.com/diy/natural-swimming-pool-zmaz02aszgoe

[Timothymaxy]

It seems much difficult than I think in the first place after reading all the post above....I just left my DIY idea ..

[Mgmny]

Posting to follow.  I like this idea and think it could be a really fun and rewarding project.  Have you made an progress on planning?

No, I'm reasonably certain my better half has squashed the project. If anyone else does, let me know!!