G'day from the land down under everybody. First things first, thanks for providing such an excellent resource for all things pool.
Apologies up front for the mix of metric and imperial numbers below.
I have just moved into a new (actually about 70 years old) house that has a fairly large (approx 85,000 litre - 22,500Gal) tiled concrete pool. The equipment is very old, and pretty low-end I think, so before it goes the way of the Dodo, I thought I should research suitable new equipment.
Thanks to TFP, I have at least got to a point now where I am balancing the water nicely - I took your recommendations and ordered the K-2006 ($100 from the U.S. but it really has been worth it). There is an old SWC installed however it does not work so I am currently daily dosing with Liquid Chlorine. The Auto Pool cleaner does not work either so I manually vacuum a couple of times a week. Bit of a digression, but just setting the scene for my lack of decent equipment...
Anyway, my first step (I think) is to establish an appropriate sized Pump and Filter. The current pump is some Hong Tong Motor Co (yep, I have never heard of it either) 1.7HP, cheap Chinese import, capable of 500 Litres Per Minute. Last week I had to give the impeller a kick to get it going so I think it's on its last legs. The current filter is a 31inch Purex Tahitian Sand Filter that also seems very tired - the pressure gauge does not work and is a non standard size. I am getting some sand spat back into the pool so I suspect either the filter is about cactus, and/or the pump is too powerful for the filter.
The inbound plumbing is 2inch, and, unfortunately, the return plumbing is only 1.5 inch (40mm).
If I base my pump sizing on an 8 hour turnover of 85,000 litres, I would be looking at something in the range of 180 Litres Per Minute (LPM). A bit of digging led me to believe that the 1.5inch plumbing is going to restrict me to a max flow rate of around 170 LPM. Now for a few questions:
1. is there any point going for a pump that can push more than the restrictions of the plumbing? (170 LPM)
2. is an 8 hour turnover enough for a sub-tropical climate (similar to Florida I guess). I was speaking to somebody the other day and they suggested I should be aiming for a 4 hour turnover and carrying it out twice a day.
I think once I have figured out my pump sizing, I can match to an appropriate Filter. I am leaning towards a cartridge filter as I like to keep it simple.
In regards to pump brands, I will probably go with an Aussie made Onga pump. Actually, they were bought about by Pentair so maybe they are U.S. made now.
Anyway, I will stop my babbling for now. Thanks again for the great site.