Pump to drain pool

[AZAA]

Any recommendations on a pump suitable for draining about 7000 gallons of water (half my pool) in 4 hours or less? I'll need to lift water from about 4' of pool depth. From there its level to my sewer drain about 100' total. I'll probably use this every year or two so it seems more economical to buy vs rent. Any thoughts?

 

[mknauss]

To do it that fast, you need a larger pump. Rent from Home Depot is probably best.

Harbor Freight has 1 hp sump pumps for under $200. You will need a 2" hose to attach to it to get the flow rates you will need. Be careful that your sewer clean out is not overwhelmed and water backing up into the home.

Better is to get a smaller sump pump and take longer to drain.

 

[JoyfulNoise]

You need a gas powered trash pump or something similar to move that much water. Also, consider where you can discharge the water as that high of rate will tear up any ground you hit it with and it’s unlikely a residential sewer clear out port can handle that much flow. If you have a swale or wash nearby, that’s the best place to send the water.

If you have to use a sewer line then you’ll need a slower pump, 1HP or so as @mknauss suggest. My 3/4HP submersible can lift water 7ft and run it out over 100’ distance at a rate of ~ 23 GPM or about 1400 gallons per hour. I did construct some 1” PVC piping with unions to attach to the pump and give it a straight lift up before attaching it to a 1-1/2” discharge hose. Larger diameters would have given me higher flow rates but I don’t need higher flow and 1” PVC is easy to work with and store.

 

[AZAA]

To do it that fast, you need a larger pump. Rent from Home Depot is probably best.

Harbor Freight has 1 hp sump pumps for under $200. You will need a 2" hose to attach to it to get the flow rates you will need. Be careful that your sewer clean out is not overwhelmed and water backing up into the home.

Better is to get a smaller sump pump and take longer to drain.

Yep...thanks. There's really no need for me to restrict it to 4 hours. I'm not doing anything else! I'll hunt for a smaller pump.

 

[AZAA]

You need a gas powered trash pump or something similar to move that much water. Also, consider where you can discharge the water as that high of rate will tear up any ground you hit it with and it’s unlikely a residential sewer clear out port can handle that much flow. If you have a swale or wash nearby, that’s the best place to send the water.

If you have to use a sewer line then you’ll need a slower pump, 1HP or so as @mknauss suggest. My 3/4HP submersible can lift water 7ft and run it out over 100’ distance at a rate of ~ 23 GPM or about 1400 gallons per hour. I did construct some 1” PVC piping with unions to attach to the pump and give it a straight lift up before attaching it to a 1-1/2” discharge hose. Larger diameters would have given me higher flow rates but I don’t need higher flow and 1” PVC is easy to work with and store.

Thanks for your response. I think I'll get in trouble with the HOA for dumping into the common area/arroyo/trail system even though it's pretty wide. Perhaps I'll do it at night when the nosey neighbors can't turn me in and then ask for forgiveness later.

 

[JoyfulNoise]

You can always try to use the sewer clean out and just monitor the house drains (showers or bath) to make sure water isn’t backing up. I would recommend doing a little bit of hard pipe PVC work to go from the pump discharge to the deck then transition to flexible discharge tubing. Many decent submersible pumps will have various threaded adapters that hook up to the discharge port. Some use garden hose adapters but those will definitely choke the flow down to 5-6GPM. 1” PVC pipe can easily double or triple that flow rate. As I said earlier I have about 15 linear feet of 1” pvc that transitions to 150’ of 1-1/2” flexible blue discharge hose and I get 23GPM on a 3/4HP pump. All in the extra pipe and glue cost me maybe $30 but it vastly improved the performance of the sub pump. I originally tried using garden hose but the rate was barely 4-5GPM.