Working Out A Odd Pool Install

[LivinLOS]

Looking for some hints.. Long story.

Firstly I have lived with a pool before, my last place had a pool but was very easy, it had an 'auto chlorinating' device that kept chlorine levels approx right for weeks even months on end from a handful of salts.. all it needed was some vacuum scrubbing every few days. I am no pool expert but I understand the basic pool design concepts I think.

I have just moved into a house that has a small pool, its only about 4m by maybe 8m and approx 1.2m deep through the entire pool. Its an overflow design with a complete one side being overflow / infinity edge. The pool has however sunk almost as much as an inch and the installers claim to be returning to brace the sunk corner and relevel the edge.

My landlord is a busy guy and I am trying to fix up the house and pool as theres quite a lot that needs attention. This isnt his residence (investment property) and hes guessing at things as much as I am. Of course the original installers should be sorting this all out but although theres assurances that they will, its the usual case of getting things done AFTER they have been paid in full, its a Thai promise at this stage so ??!!

When I first moved in the overflow wasnt working at all !! They had configured the plumbing to drain from the pools main sump (and theres only one sump.. I thought that was a dangerous pool design no no !! possible to create a vacuum suction issue !! perhaps this is considered OK as it should be configed to overflow not drain ??) and then out the 2 pump outlets on the base of the pool floor. We also guessed / worked out the cleaning vacuum valves etc. At this point I was told, and came to the conclusion, that there was no surge tank fitted at all !!! Obviously with the drain / pump cycle configured this way there was no overflow action and the pool was losing water both over the overflow while used, and through evaporation. I filled it with a hose and was at this stage baffled and annoyed. I had a guy experienced with pools look at it and he said no surge tank fitted, water that went over the overflow simply went to wastewater !! and the pool was just a bad install live with it (wrong info) !!

Further discussion with the landlord showed that the overflow did work in the past, and that he is sure there is a surge tank (presumably but unverifiably, with a top up water level system), some messing around showed what I took to be part of the backwash system is a pipe leading to a buried underground surge tank.

With valve reconfig I can make the system pump out through the base of the pool, over the overflow into the surge, and almost properly back to the pump. Now I have painted the picture I will at last get to the worry.

When I have it set up this way the system is configured to pump in the only way I can see to be successfully using the overflow but the big problem as I see it is the surge tank is below the level of the water pump !!! When operating the pump in the (not correct) basic way of pool sump through pump and back to pool, without the overflow, then the pump is, as it should, pumping 100% water with no air in the system.

However when I set the config to pump into the pool, out the overflow, through the mystery underground surge tank and back to the pump, because the surge tank is lower than the pump the pump sucks air. This is especially bad as the pump just kicks in, in my guess because theres little or no water level feeding back to the surge yet. Yesterday I experimented during a heavy rainstorm (so that the overflow was naturally flowing, and presumably all those surge tank pipes were full of water way above the surge tank) by switching from sump drain to overflow / surge tank for the water source and even then when the overflow was already at full flow the surge tank provides less water than the pump pushes !! Perhaps 70 water 30 air.. Of course this then pushes air bubbles through the system but mostly I am fearful for the pump pushing air (my last house a pool cleaner messed with the valves and when the pump kicked in with no water it burnt a pump out).

Remember this is when the system is already overflowing and full of water, If I were to start the pump on the overflow system cold, as it would on the timer left alone, then the surge tank sends up a trickle of water, the pump is working flat out on 10% water 90% air and I have no idea how long it would take to create enough surge to create a feedback loop. Even at best it only made 70% remember.

Right so thats the long story. Based on that above info.

Isnt a surge tank below the level of the pump a total screwup ??

Is there any case where a surge tank can be done that way and work ?? I am thinking that the surge has to have an autofill and an overspill valve, the overspill valve will break any airseal and prevent a 100% water syphoning system, and I doubt the pump is designed to pull as well as push ??

Does air into a pump risk damaging the pump ??

The reason I am trying to solve all this myself in my own mind first, is I have already had one pool guy give bad advice, and I have been moaning at my landlord about a collection of jobs that I see as structural jobs. So I want to at least be correct if I am moaning. Especially as this may require some kind of redesign and replacement of the surge tank system and appears to not be just a 1000 baht problem.

[LivinLOS]

I should also point out.. Now that I have realized the mystery pipe leading off through the floor is the surge surge tank outlet (to pump) there appears no facility at all to backwash the sand !!!

I am of the opinion that the pool installer is a total cowboy !!

[Bagwain]

1st / you need to find the surge tank (if there is one ) If not you will need one installed and it needs to be at least 7% volume of the pool. (3-4 cube)

2nd / nearly all surge tanks are below the pump. The feedpipe has a non return valve or foot valve attached.

3rd / yes air in the system will more than likely burn the impellor out before the pump dies.

4th / I wouldn't be suprised if the wrong filter & pump combination is installed as well.

You are experienced with salt chlorination! This is the best way to go. You have to ask for a pool not to be salt in Oz!

I trouble shoot a lot here in Pattaya with swimming pools as I have had experience with over 1000 commercial pools in Oz. NZ and now Thailand. The standard of work here is atrocious. But I do get a lot of work out of it. I.e. Non water proof concrete, no wet bar, wrong steel, cement instead of glue for the tiles, kitchen tiles instead of pool tiles, poor a grouting, bad plumbing and wrong combinations of filter and pumps & no or inadequate surge tanks.

Some of my customers include - Lagunna complex and Pacific Club Spa in Phuket, Sheraton Royal Orchid & Metropolitan Hotels in BKK, Kow Keow open Zoo, Ban Sabajai Health Resort and Birds & Bees Resort (Cabbages & Condoms) Pattaya. Plus dozens of domestic clients/Customers.

I also do water filtration to potable standards.

Trust this helps!

PM me if you would like a consultation.

[Naam]

Long story.

it's rather early and i swear i didn't have a drink yet (although the Old Lady is abroad and not in control of the bar). and after reading your pool "dissertation" three times i still have no idea what you are talking about

[MrPaddy]

Lol, just paint a peace sign on the floor and all will be good in the morning.

[LivinLOS]

Long story.

it's rather early and i swear i didn't have a drink yet (although the Old Lady is abroad and not in control of the bar). and after reading your pool "dissertation" three times i still have no idea what you are talking about

Early ?? or late ??

Doesnt matter I havent slept in days !!

[LivinLOS]

1st / you need to find the surge tank (if there is one ) If not you will need one installed and it needs to be at least 7% volume of the pool. (3-4 cube)

2nd / nearly all surge tanks are below the pump. The feedpipe has a non return valve or foot valve attached.

3rd / yes air in the system will more than likely burn the impellor out before the pump dies.

4th / I wouldn't be suprised if the wrong filter & pump combination is installed as well.

You are experienced with salt chlorination! This is the best way to go. You have to ask for a pool not to be salt in Oz!

I trouble shoot a lot here in Pattaya with swimming pools as I have had experience with over 1000 commercial pools in Oz. NZ and now Thailand. The standard of work here is atrocious. But I do get a lot of work out of it. I.e. Non water proof concrete, no wet bar, wrong steel, cement instead of glue for the tiles, kitchen tiles instead of pool tiles, poor a grouting, bad plumbing and wrong combinations of filter and pumps & no or inadequate surge tanks.

Some of my customers include - Lagunna complex and Pacific Club Spa in Phuket, Sheraton Royal Orchid & Metropolitan Hotels in BKK, Kow Keow open Zoo, Ban Sabajai Health Resort and Birds & Bees Resort (Cabbages & Condoms) Pattaya. Plus dozens of domestic clients/Customers.

I also do water filtration to potable standards.

Trust this helps!

PM me if you would like a consultation.

Thanks..

I am on phuket so out of your way and partly this thread is to point to the landlord in case it needs non trivial work. I dont mind solving the problem but I dont want to pay to solve his problem !!

1) there is a tank.. but its been buried under some lawn !! cant inspect or maintain or anything.

2) Heres where you lose me then.. What gets the water out of the lower surge tank and 'up' to the pump ?? Can the pump safely 'suck' water if its an air free system ?? I thought they were only to push not pull ??

My last setup was pool (large) with overflow into kiddies pool, that shared a level with the surge tank, that was all above the pump room. Gravit in that case keeps the surge tank water flowing to the pump without air in the system.

3 and 4) thanks.. clear now.

[DrDave]

Your pool design sounds nearly identical to mine (in your old neighborhood - top of the hill). The bottom of my surge tank is probably about 1 meter above the level of the pump (and about 15 meters away).

Attached is a crude schematic that show the plumbing you should have. There should be three inflow lines (main drain, vacuum and surge tank) tied together via a manifold, and then connected to the pump inlet. Each of these three lines should have a valve on the pool side of the manifold so that you can regulate how much water (if any) you want flowing through each.

You probably have a single return line, from which each of the return jets in the bottom of your pool is connected.

If you find that the surge tank isn't behaving properly (such as water draining from the pool into the surge tank when the pump isn't running), then you need to check/clean the foot valve at the bottom of the surge tank. This valve prevents water from backflowing from the main drain into the surge tank through the manifold (e.g. water seeking equalibrium across the two resevoirs - pool and tank).

As for sucking air - mine seems to do the same thing whenever switching off the main drain, and switching on either the vac or surge lines 100%. Air bubbles come out the return jets for a a few minutes - but then after all the air clears, no more bubbles. If you're concerned about this - gradually close the main drain, while gradually opening your surge inlet valve to ensure that the pump is always being fed primarily water.

I know that when pumping water out of the surge tank and into the pool, I've run the tank dry and the pump has sucked air for a couple of minutes with seemingly no damage to the pump. I wouldn't suggest letting it run with air longer than a couple of minutes, though.

[Bagwain]

I am in Phuket quite often and I have some colleagues that work there and they know what they are doing.

By the way the "DrDave" Baffle that he mentioned is a crop of shit.

It is typically Thai and they just copy to make things easy.

Each pipe needs to have its own feed and some times this needs to be dual connected.

Please don't listen to the wana be backyard experts. But (up to UUUU)

[DrDave]

I am in Phuket quite often and I have some colleagues that work there and they know what they are doing.

By the way the "DrDave" Baffle that he mentioned is a crop of shit.

It is typically Thai and they just copy to make things easy.

Each pipe needs to have its own feed and some times this needs to be dual connected.

Please don't listen to the wana be backyard experts. But (up to UUUU)

Huh? What baffle?

I was merely documenting the design of my pool mechanicals. I live in the same general area, and his pool may have the same design - possibly built by the same people. I wasn't suggesting that this is an optimal design. All I know is that it works just fine. Sometimes its just helpful to have a diagram of what you have to make it easier to operate - especially if its a rental house and you have no other documentation or instructions available.

[Bagwain]

I am in Phuket quite often and I have some colleagues that work there and they know what they are doing.

By the way the "DrDave" Baffle that he mentioned is a crop of shit.

It is typically Thai and they just copy to make things easy.

Each pipe needs to have its own feed and some times this needs to be dual connected.

Please don't listen to the wana be backyard experts. But (up to UUUU)

Huh? What baffle?

I was merely documenting the design of my pool mechanicals. I live in the same general area, and his pool may have the same design - possibly built by the same people. I wasn't suggesting that this is an optimal design. All I know is that it works just fine. Sometimes its just helpful to have a diagram of what you have to make it easier to operate - especially if its a rental house and you have no other documentation or instructions available.

Dr Dave,

The Baffle that I refer 2 is the pipe work that they typically put in above the pump.

Can't give to much away as they will just copy the way it should be done.

Cheers

[LivinLOS]

Thanks for taking the time to reply guys...

What I still dont understand tho is how the surge tank can be below the pump and the water flow 'up' to the pump.. I think thats the root of the problem.

I also dont appear to have a backflush valve or system on there..

I guess I just need to insist that the landlord sorts it out. I dont want to tun the overflow on and burn his pump out.