New pump for an old pool

[matrim72]

PoolDoc,

Thank you for the quick response!

I find myself with more questions. Everything I have seen says plan for an 8hr turnover. You based your calculations on a 6hr turnover. Why is that? Preference?

Second, I have 65 feet of pipe between the skimmer and the pump, but it is almost all horizontal. I think there will be only about a foot of vertical head. Which is more relevant? My gut says the horizontal pipe will not bother the pump (at least once it is primed).

Third. Where did the 13 gpm/sft come from for the sand filter? All the quotes back from pool places put me at the 24" filter, not the 30" one, so I am curious what are the advantages.

Lastly, I need the walmart kit in addition to the taylor kit? What is OTO?

Again thanks for the advice and the wonderful links!

Matt

[PoolDoc]

Horizontal pipe is a problem because of the amount of air it often will contain. "Self-priming" pumps have some capability to deal with air, but not lots. And, what capability they do have is usually lost at low speed. So, it's necassary to start on high, run long enough (15 minutes?) to make sure priming has occurred, and THEN switch to low. Putting swing (not: spring!) check valve inline BEFORE the pump can help, but be CAREFUL to orient the valve properly, make sure it's testable and serviceable (debris can get caught in them), and that it's a good valve.

OTO is the only almost 'bomb-proof' chlorine indicator: if says you have none; you have none, and if your chlorine is VERY high, it will still indicate. It's also cheap.

The DPD-FAS system in the K2006 is MUCH more accurate, but not quite a bomb-proof. What many experienced folks here do, is use OTO for quick daily testing, and DPD-FAS for periodic complete tests.

[matrim72]

I guess I should have been more clear about the horizontal pipe.

Since we were talking about feet of head, what is the conversion of horizontal pipe to feet of head? I think I am probably about +1 foot of vertical head from the level of water in the pool, to the placement of the pump, but its the horizontal run which seems to be dictating pipe size and pump.

I think the chart you posted shows a different "quality" of pump based on which efficiency curve you need to be on, which in turn is based on flow rate (based on pool size), and dynamic feet of head (based on pump placement). Is this interpretation not correct?

[PoolDoc]

I guess I should have been more clear about the horizontal pipe. Since we were talking about feet of head, what is the conversion of horizontal pipe to feet of head?

Static head is not affected by horizontal pipe; only by vertical changes. Dynamic head is not effective by either horizontal or vertical changes, per se; rather it's a function of pipe size, interior surface and total length, regardless of elevation changes.

[mas985]

A WFDS-3 or WFDS-24 should be able to easily turn that pool over in less than 6 hours.