Custom Pool, More Like A Pond & Poor Circulation

by Jennifer H.
(Indianapolis, IN)

Full view of freshly filled pool

Full view of freshly filled pool

Full view of freshly filled pool
I was actually photographing the fox, but you can get a better idea of the composition of walls and floor when pool's empty. Also see the skimmer box on the far left side.
Better view of waterfall, steps, and the filter off to the left.

My primary problem is that we let our landscaper talk us into creating a "pool" for us, and I need to figure out if there's anything we can do to overcome it.

He had this idea for a beautiful pond that we could also swim in and treat with chemicals if we desired.

It's oval or kidney-ish shaped, about 38' x 23', and ranging from only 2' to 3'10" deep, so I estimate it right around 15,000 gallons.

The bottom is poured concrete, while the sides, stairs, and waterfall are rocks/small boulders held together with cement and mortar.

Obviously this makes the sides very uneven, and I literally need a toothbrush to clean between some of the rocks on the walls because all the pool brushes are too big to get in between them.

Here's the kicker...the only thing we have for circulation is a waterfall, with about a 5' drop, where the water falls into the deep end of the pool.

The only pump is in the skimmer box at the shallow end furthest from the waterfall. There are no return jets, no main drain, and nothing to hook up a vacuum to (I use a handheld PoolBlaster Max).

Everything about the skimmer basket (no flap, just a hole left between the rocks) to the plastic faux rock cover is something you'd get from a pond (not pool) shop.

We did add a large sand filter (originally it had none), one designed for like a 60,000 gallon pool that the water passes through just before making the hill up to the top of the waterfall.

While we thought the addition of the filter was necessary, it did slow down our waterfall flow pretty substantially.

And while you're supposed to let your filter pressure go up 10 psi before backwashing, we have to backwash much sooner (increase of about 3) or we only get a trickle from the waterfall, which I assume is a worse problem due to even less circulation.

It's in full sun all day until about 5:30 pm, and because of the uneven rocky edges, we've found no effective way to cover it...ever.

During the fall/winter/spring, we just let it turn into a nature pond full of disgusting creatures and once we see gazillions of tadpoles in the late spring, we pump it all out into the woods, chlorine bathe it, and then refill it with city water for the summer.

I have a REALLY hard time keeping the free chlorine level up, despite everything else being in range (ok, so my alkalinity and ph tend to stay too high no matter how much muriatic acid I drop in there).

I use liquid chlorine to shock every week or two, and stabilized granular, about 2-3 cups every evening. But by the time I get home every afternoon, test strips say ZERO.

I have been aggressively fighting (and losing) a battle to green algae all over the walls of the pool. I add an initial dose of algaecide (whatever standard HTH stuff they sell at Wal-Mart), spend 2 hours scrubbing the rock & cement walls with my toothbrush, and then vacuum the next day and scrub again.

No improvement. I do the same thing 2 days later. I've done this 6 or 8 times, and every day when I get home from work, the algae seems to be worse.

I think it's next to impossible to fully brush it away because the side surface is so porous.

Obviously, this has made the chlorine problem even worse, and now I also have an oily film on the surface (presumably due to algaecide overdose).

But I think it's all stemming from lack of circulation.

Is there ANYTHING I can do to fix my massive problems?

I've wondered if it would help the waterfall fall harder by adding a larger pump or a 2nd pump (The landscaper left a pvc pipe running into the deep end side wall flush with the wall, about 6" from the pool floor, and the pipe comes out of the ground near the filter where we could presumably add a pump out of water loud, right?)

Everyone thinks our pool looks amazing, but they have no any idea how much it is torturing me!

Can you help?

Thanks for the question Jennifer

And I agree, the pool looks amazing. My parents had a similar pool, but not as big, in Arizona.

First I want to address the size of depth of the pool. Being that it's only 2 - 3 ft. deep and a larger surface area, I would argue that the water temperature would be a bit higher than a regular 15,000 gallon pool in Indy. Let's say 3 - 4ft shallow end and 8 - 10ft deep end.

If this is the case, the extra heat will chew up the chlorine faster.

I'd like to have the rest of your chemical readings:

CYA (cyanuric acid/stabilizer)



Calcium Hardness

Metals (iron and copper)

Total Dissolved Solids

It makes troubleshooting much easier and the process of clearing up your pool will go much faster.

You can get this done at your local pool store.

Without these numbers I'm just guessing at what the problem is.

Get a Taylor FAS-DPD K-2006 pool test kit and lose the strips. You want accuracy and the DPD kit will give you the best.

Pool Water Testing

Water Testing Kit

My parents pool had 2 motors, one for the filter and one for the waterfall.

You should have a designated pump motor for each because if you don't you're going to keep having the same issue, which is loss of circulation.

Proper circulation and filtration is vital in keeping a pool clean and clear.

You say the alkalinity and pH are high, but that's relative to each pool owner. I had a question from a visitor on how to get his chlorine level down. It was way too high, at 4.0ppm.

That's not too high. You should keep the level between 1.5 - 3.5ppm, so 4.0 is not far off.

Your chlorine issue could be either not enough or too much stabilizer (cyanuric acid/CYA). It's hard to say without the reading.

The chlorine is 7.5% of your CYA level and that is 30 - 50ppm.

If you keep using a stabilized form of chlorine every evening and for weekly maintenance, the CYA might be very high. I'd get a water sample to your local pool store right away and have them do all the tests.

The only way to reduce the CYA is to to a partial drain and refill.

You can have a CYA level of 100, but you'll need to bring the chlorine level up in proportion to it. If it's 100, then the chlorine level will need to be maintained at 8ppm.

Now for the algaecide. An algaecide is used for preventative measures only, not to get rid of already existing algae.

For your Walmart HTH algaecide, do the ingredients look something like this:

Active ingredient
Alkyl(60%C14, 30%C16, 5%C12, 5%C18)
dimethyl benzyl ammonium chloride...........30%
Alkyl(60%C12, 32%C14) dimethyl
ethybenzyl ammonium chloride.................30%
Inert Ingredients...................................40%
Total 100%

If they do it's a linear quat, not a polyqaut. To the best of my knowledge the only polyquat that HTH has is the Aglaecide 30 which is 30%.

You want to get a true PolyQuat 60%. This is only for a little insurance against algae, not to kill it.

If you're pH is high, say above 8.0ppm, you're only using about 25% of your chlorine. Then to possibly have a high CYA out of proportion to your chlorine, and the result will be virtually no sanitizing.

Then a high alkalinity, which should help lock everything in place, and you're really behind.

I can tell you exactly what to do to balance your chemicals when I get a full list of your readings, but, it won't make any difference if you first don't have proper filtration and circulation.

It's a combination of things that make the pool work.

If you can, get a pump for the waterfall and a way to get the filtered water back to the pool.

I'm looking forward to getting your chemical readings so we can get your pool back up and running and you can have fun with your family.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Chemical Questions" category.

Swimming Pool Questions and Answers

Check back to this post for answers.

Hope this helps and have a great Summer.


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