Building Small Waterfall and Pool - Do I need chemical?

[Paul Alford]

I am building a small pond/pool in my own back yard for my own use. This is mainly to visually enjoy but my wife and I wonder if we could even use it to "cool off" in the summer too. Its 9' wide x 8' long x 4.5' deep, so about 2420 gallons. I have a brick wall on one side that will have a waterfall on it. There will NOT be fish or any plants...just clean water. I want a pump at the bottom to cycle the water and send to the op of the 6 ' wall for the waterfall.

1. What pump do I need? Filtration? Size? I want soft flow of water on fall. Looking at 2400 GPH pump (I think)
2. Do I need to add chemicals if we want to keep clear water and get in it to cool off in the summer ?

https://www.paulalfordphotography.com/wp-content/uploads/fountain1.jpg

[Denniswiseman]

Hi Paul
You would only need a small pump
There is no need to turnover the pool contents in an hour
I would also suggest a small filter to keep the water clean
I would definately add chemicals because if you don't it will become a pond also the waterfall will constantly raise your pH so there will be a regular testing of the water
Depending on how often you will use it, keep it tested, clean, sanitised and balanced all year, you might be better off turning it into a pond

[Teapot]

Paul, what are you intending to use to finish the pool/pond, possibly a pond or pool liner or plaster etc?
If you are using a liner you can keep the water alkalinity low 25-40ppm then the pH won't rise. As Dennis has said and I second, for your own safety you should treat the water with a bit of chlorine so you'll require a water test kit and not dip strips. If you use the stabilised chlorine tablets pH won't matter anyway as it will stop rising.
If you can get a variable speed pond pump you could slow it down for filtering but speed it up for back washing of the filter (sand) or maybe you are considering a cartridge filter. either way it will cost very little to run. You'll need to consider some form of surface skimmer pond or pool as all dirt enters from the surface that is the best place to remove it.

[Paul Alford]

I still have to dig out the dirt bottom and was going to use mortar or concrete to solidify the walls and floor...then apply a thick drylock paint or similar sealer on the surface of the mortar so its waterproof and softer to touch. Since it so small I can just use a hand skimmer to keep the falling pine needles, leaves and bugs out. I was thinking to have a recessed spot at the bottom floor (nearest brick wall waterfall) to install the submersible pump so we wouldn't kick it if we get in. I am not getting a regular big pool pump with sand filter. I think some of these submersible pumps have filtering too. I am looking at this pump since it will turn all the water around so it wont get stagnant.
https://www.amazon.com/dp/B005N0HSN4/?c ... _lig_dp_it

[Teapot]

To be fair unless you are sitting by the pond ( not going to call it a pool any more following your post.) You'll not keep the debris down sufficiently, the bottom will soon become biofilm and as slippery as an ice rink. The small pond pump has only a course foam and will not keep the water in a satisfactory condition. Not suggesting you need a pool pump just a bit of water flow through a proper filtration system. Small sand filters are available for above ground pools often 2nd hand.

If you don't want my advice and prefer to do what you want that's fine but you asked for advice.

[Paul Alford]

I do appreciate your advice Teapot and I am listening. I am just sharing what I am "thinking" to do...this is why I am here asking for help.

My wife and I do want to be able to get in the water so we call it a "pool." To me, a "pond" is dirty, has plants and maybe fish and we dont want any of that. So you do advise even as small as it is, I would need a regular pool filter system with sand? Right ? So something like this.... https://www.amazon.com/Intex-28633EG-Kr ... 160&sr=8-5

since it pumps 2500 GPH (since I want to turn over my volume of 2420) every hour. I am also wondering what kind of flow that will bring to the waterfall top. Where the outlet hose returns back to the waterfall top...if the force of the water would be too much and jump off the first ledge and just too fast to trickle down the other ledges. I guess I can put a "T" fitting on the end to help redirect the flow to help the water stay on the waterfall as well.

[Teapot]

Hi Paul, The Amazon advert you linked to is the really pathetic cartridge version which should be avoided.
The better option is a sand filter
https://www.amazon.com/GAME-Complete-Re ... JX6SJ&th=1

As you quite rightly mention the flow could be a bit strong but you could divert it so some along with the waterfall is pushing the water towards the surface skimmer. If possible don't use sand but buy Activate filter glass by Dr Dryden costs a little more but as you'll not be using much not that much more but it out performs sand by around 4 times and you will never need to replace it. Try to avoid other glass that looks like it, they simply do not perform as well and are not self sterilising.

You could still use a variable speed pump from a pond coupled to the sand filter so you can have a slower flow but you'll also be able to up the flow to back wash the filter. Alternatively fit a speed controller to that pump setup, you'll recoup the additional cost in electricity saving. (look at my signature, My pool 12,000 gallons runs on 60 watts).

Esthetic wise, you probably would not want a bright blue pool liner, pond liners are available as are pool liners in darker colours more suited to your requirement. Liners make pools easier chemical wise to look after. If you are rendering the walls then use something designed for pools and permanent immersion in water, many have tried with ordinary occasional wet products with disastrous results. There are also paint on coating used for ponds like Impermax. Surface skimmers for ponds are also available in black so not as obvious as a brilliant white one, they are exactly the same apart from the colour.