Pump/Filter Sizing Mytery

[Vinyl_Guy]

We need a picture.

The higher the resolution and more detailed the better. If you are not able to upload it to a location, I can provide one for you if need be.

I'm thinking this is not a standard gunite pool, and if it is, it's just been through so much that it doesn't resemble one anymore.

I have a hypothesis that at the lowest the water will only drop to the level of the shallow end, which was dry when we first looked at the pool - the rest of it was full. The pool had not been touched in probably 2 years. We walked in the shallow end and launched massive chlorine bombs from the water's edge, which was actually where the drop to the deep end took off.

That's very telling. Sounds like this fiberglass type thing I've yet to wrap my head around, could be the cause of a majority of the problems, when talking water loss.

Cracks appear to be from about an 1/8th anywhere up to 3/8", maybe even 1/2", but I don't think that bad. I have two cracks in the bottom I have spotted that run the whole width of the pool (expansion joints?), plus a few other, lesser faults.

Purposeful "expansion" type joints would only occur in a concrete pool and not a plastered gunite pool (maybe rarely).

Is the pool "painted" that you can tell? That's a dead give away of "concrete construction", of some type. Or is the "bottom" (shallow end floor,drop off, and deep end), a white (possible not pure white) smooth substance?


Your idea for the landscaping drains sounds about right but remember there's also a large volume of water that is shed from that section of deck too. Getting at the water as it comes down your hill is good, but the water that falls onto the deck and then is shed back to that area can cause just as many problems behind the walls. Although it's probably the much lesser amount of water compared to the hill it could still be enough to cause problems.

But dig this: This pool is 40' long. There are two serious cracks in one deck - the "hill" side - that both run on a slight diagonal outward, from the pool rim to the edge of the deck: imagine a shape with one side 18' long, the other side 20' long, with symmetrical ends angling out from the short side to the long side (the "hill" side.) They both start about 11' from the ends, measuring to the "short" side if you follow me. And the concrete between these cracks is dropped about 3/4", maybe less- I haven't actually measured any of this precisely.

Are these diagonal lines/cracks perfectly straight? If so the deck has dropped right at the point it was predicted it would happen after the pouring of the deck. This would have been a different kind of "expansion joint", a relief joint. It's a weakened indentation, cut, or "score" in the concrete put there to make any pressure that will eventually crack the deck occur in a uniform manner. Think of the sections of concrete side walk. Even though the lines in them might not extend all the way through the concrete that is where they will most likely crack when "heaving" happens. If they (the diaganol lines) are not perfectly straight then they probably left them out. Which is right were they are normally put (diagonally at the corners), and periodically in long stretches too.

Finally, concerning the returns, I have slightly fizzy, bubbly flow from the jets. Hopefully they are all okay because they are certainly deep.

That's most likely not a problem with the return line. Rarely will water being pushed through a return line, pick up air from that line and dispense it into the pool. A return line is more likely to push the water out of any "leak" while running. Air at some point is being introduced into the loop and thus being fed into the pool. Air most likely can't be introduced into the system with out it being "sucked" in. So water leaking from your filters, pumps or other systems topside are probably not the source (believe it or not), those are places water is being "pushed" out. Valves, threaded fittings, loose clamps form the suction of the pump, on out, is probably the source of the bubbles.

If you can see the bubbles in a your pump "chamber", try this: Get a watering can or garden hose that you can regulate. Start where the suction lines come up out of the ground and trickle (pour till the fitting has water all around it, and continue to do this) water on any fitting (elbow, coupling, bushing etc), and valve. See if the bubbles go away or are reduced as you trickle the water all around these "connections". What happens is, the constant flow of water effectively seals the air leak temporarily. It might be in several places, so it make take trickling water on two different ones. Work your way back to the where the suction lines ends up at the pump. Even this fitting might be the culprit. Or any lid, threaded plug or other thing in the pump body itself.

Like I said though at this point I think we need a picture. I still can't picture (no pun intended) this fiberglass type section your describing. I think I understand "where" it is, but why it's there and what its function is, I have no idea. Could it possibly be a section where the plaster/gunite/ or concrete has actually completely failed and dropped away?

If you need help figuring out how to get a picture here (on the forum), or to me, we can work it out. Emailing me is activated in this forum as well as several Instant Messenger services I use.