External pump setup to fight wildfires from pool

thedeependent

Active member
Jun 30, 2024
38
SoCal
looking for recommendations on how to best utilize my 30k gallon pool to lower the risk from fire damage in an event of a wildfire. Should I be looking at trash pumps? Some type of sprinkler setup? Any direction would be greatly appreciated.
 
I'm sorry for your predicament out there. Horrible. Stay safe!

Trash pump would be the best, particularly if you want to get large volumes up 2-3 stories.

1736478357812.png

You can look into a sump pump too...
This 1/2 horse pump as an example:
You want to look at the head curve for any pump you might consider...here is the curve for the sump pump above.
Screenshot 2025-01-09 220023.png

Then consider the application. Max head is 33' for the sump and 91' for the trash. Need to subtract the depth of the pool from deck, so if your deep is 9', then the max head would be 24' for the sump from the deck up.

If you do get a sump, make sure to get a 12' or 15' cord...or it will be useless.

With your pool pump, AND you have a main drain, AND you can turn off skimmers, AND you have unions on your pump, you could connect a hose to the outlet of the pool pump and pull water from the bottom of the pool. You could calculate your existing head (@mas985 might help with that), then back into the same calculation above with your pump curve (below). Note that your head will rise when you use the pool pump as the pool water is depleted. I'm assuming that you are potentially under a time crunch, but you can also plumb in a spigot after the output of the pump and connect a hose that way...requirements above still apply...you have to be able to pull from the bottom and close off skimmers.

1736479030570.png
 
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I'm sorry for your predicament out there. Horrible. Stay safe!

Trash pump would be the best, particularly if you want to get large volumes up 2-3 stories.

View attachment 623996

You can look into a sump pump too...
This 1/2 horse pump as an example:
You want to look at the head curve for any pump you might consider...here is the curve for the sump pump above.
View attachment 623994

Then consider the application. Max head is 33' for the sump and 91' for the trash. Need to subtract the depth of the pool from deck, so if your deep is 9', then the max head would be 24' for the sump from the deck up.

If you do get a sump, make sure to get a 12' or 15' cord...or it will be useless.

With your pool pump, AND you have a main drain, AND you can turn off skimmers, AND you have unions on your pump, you could connect a hose to the outlet of the pool pump and pull water from the bottom of the pool. You could calculate your existing head (@mas985 might help with that), then back into the same calculation above with your pump curve (below). Note that your head will rise when you use the pool pump as the pool water is depleted. I'm assuming that you are potentially under a time crunch, but you can also plumb in a spigot after the output of the pump and connect a hose that way...requirements above still apply...you have to be able to pull from the bottom and close off skimmers.

View attachment 623999
Thanks for the thorough write up! I am thinking the trash pump would make the most sense for our use case. Would having a longer hose cut my max head by the length of the hose?

Also, would it makes sense to get a higher end brand such as a Honda if I can’t find a predator in stock?

Thanks again.
 
Thanks for the thorough write up! I am thinking the trash pump would make the most sense for our use case. Would having a longer hose cut my max head by the length of the hose?
Laying horizontal there is no HEAD, horizontal length will affect friction loss. Friction loss in the pipe depends on velocity, pipe diameter, material, fittings, valves, etc... Vertical orientation will add head 1:1 (close enough for government work) in feet.

Here is a honda option: Honda WB20XT4A - 164 GPM 2-Inch Water Pump

Note, MAX PSI is 45.

Depending on how you configure this, the hoses, you want to be careful on the max PSI.

  • A 2" hose at 100' would be about 20 PSI or so at 150GPM (Full Throttle).
  • Adding another 100' of garden hose would add significant PSI....at 12 GPM, pressure on a 3/4" hose would be over 200. 😱
  • If you are thinking about doing this 2" down to 3/4" garden hose, I would err toward a larger, like 1.5" discharge and run less than 100GPM. Or if you are going to use a garden hose, then you would need to run your GPM down at close to 10gpm (idle or close) with a 100', 3/4" hose.
  • With a 25' 3/4 hose connected to the 100' 2", your pressure loss would be 5, and likely 30-40 GPM and be safe (Garden Hose Flow Calculator 3/4", 20psi and 25' yields a 20psi).
  • Shorter and larger is your friend on pressure. You can always run the pump slower to reduce output if necessary. Even going up to a 1" hose, a 25' would yield 20PSI at 100GPM...a significant improvement, and would allow 100' of 2", with 25' of 1" and 40 PSI. Would be plenty of flexibility to roam...
  • Or just get 100' of 2" with a nozzle and be done. You can run any speed you want to vary GPM.
  • Start slow with the Pump speed in any case.
  • Double check pressure ratings on your hoses.

1736490487921.png
1736491289431.png

Also, would it makes sense to get a higher end brand such as a Honda if I can’t find a predator in stock?
I only gave you that link because it was the cheapest option, given that you are not using this regularly...but yes, any trash pump would work. Check the performance.

Depending on what you are thinking about doing, this guy connected his Trash to pvc reducers to use it as a garden hose....you don't get a real sense of how far he is able to spray from a garden hose, but he is pretty impressed with how far he is able to get it to go. You may be able to spray up easier than getting the pump to pump to the roof. No idea the volume you might expect. Either way, a decent TRASH pump, should do the job.

 
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would it makes sense to get a higher end brand such as a Honda if I can’t find a predator in stock?

It would make sense to get a better pump regardless. In my opinion.

I've recommended the Wick 80-4H pump here before, as a representative example of a reliable pump that's suitable for this application. It's designed for firefighting and is built much more thoughtfully than the Predator pump. It has useful features that the Predator doesn't, it's about 1/3 the size and 1/3 the weight, and its specs are better for wildfire protection -- and it actually meets its published specs. Plus you can get parts, lots of accessories (including ground and rooftop sprinklers if you want to make this a big project), and other support.

With the necessary accessories (hoses, nozzle, tools, etc.), it costs about three and a half times as much as the Predator with its accessories. But on the other hand, it'll probably work when you need it to.
 
I've recommended the Wick 80-4H pump here before
That's a nice pump...Lower flow and higher pressure room...and great head...1/5" hose...
  • Maximum working pressure – 60 psi
  • GPM – 55 gpm free flow / 7 gpm when using a 3/16″ nozzle
  • Maximum lift – 120 feet
 
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@thedeependent, more-involved solutions also exist -- like a pool-fed sprinkler system that connects to an app on your phone and can automatically saturate your property with water and (optionally) foam when fires are within a few miles of your house. No personal experience with this company, but a friend of a friend runs it and he seems smart: frontlinewildfire.com
 
I know nothing about this topic, but that's never stopped me before! I would want input from my local firefighters. Of course, you're not going to find any now that can stop and chat! But I periodically have conversations with mine and learn things I would have never thought of. How to trim trees, for example (my neighbor's a firefighter, so he's a great resource for me). I also have had conversations with the captain at the firehouse closest to my house. I would think they would know best about how to prepare for an approaching fire. What suppressants to use (water or otherwise). How to lay them down. And when to. Stuff like that. You might be preparing to fight with your water pump, when something like that might be ineffective, or rather less effective than something better. Maybe there's a better MO to use, and so a better way to spend that fire-prep money.

You might be all ready with your pump, only to have the fire or police departments force you to leave before you can even use it. Maybe there would be something else to do before you were evacuated that would have a much bigger impact than spraying pool water here and there.

Like I said, I know nothing about this topic, so I'm just brainstorming with ya. And maybe you know a lot about this. But if not, that's all the more reason to seek out those that do, and to use what they know, and to heed their advice, before you spend the money.

Either way, whether a pump is the way to go or not, I sincerely hope you never have cause to need it!
 
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Wb
Maximum pressure45 psi
Discharge capacity164 gal/min
Discharge port diameter2" NPT
Total head lift105 ft.
Suction head lift25 ft.


Wh
Max Pressure: 61 psi
Discharge: 119
Inlet/outlet diameter: 2″ x 2″
Total head lift: 147
Suction head: 26

I’d go with the wh20xt…
 
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Excellent advice from @Dirk.

And I agree with @PoolStored: What you want for this application, all else equal, is high pressure / high head, not high flow -- you're not trying to empty your pool as quickly as possible; you want the pool water to last. The pump I linked to earlier even has a clutch that disengages when the engine is idling, so the water only flows when you want it to and none is wasted.
 
looking for recommendations on how to best utilize my 30k gallon pool to lower the risk from fire damage in an event of a wildfire. Should I be looking at trash pumps? Some type of sprinkler setup? Any direction would be greatly appreciated.
Personally having over 33 years of experience on this subject, here’s my 2cents.
It’s all about having your property secured and prepared for not catching fire prior to the actual event occurring.
Staying behind and defending your property can get dangerous really fast especially in Sant Ana wind conditions (been there done that).
That being said, sprinklers on the roof typically from what I have personally experienced do not work as well as a mobile fire hose, roofs are designed to shed water and they do it quite well. Most wild land/structure fires I have responded to do not start on the roof, but from inside the house such as embers entering the attic or from windows breaking from radiant heat and interior contents catching fire.
Keeping flammable materials (all types) away from the structure you are trying to defend is your best protection for the structure you are defending.
I have personally whiteness items such as plastic kids toys that were located up against a structure that caught fire and extended to the interior of the structure from a window that the toys were located under, unfortunately due to the intense winds the structure was lost.
Lots of information can be found on what your looking for, hope this helps IMG_0425.png
 
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Personally having over 33 years of experience on this subject, here’s my 2cents.
It’s all about having your property secured and prepared for not catching fire prior to the actual event occurring.
Staying behind and defending your property can get dangerous really fast especially in Sant Ana wind conditions (been there done that).
That being said, sprinklers on the roof typically from what I have personally experienced do not work as well as a mobile fire hose, roofs are designed to shed water and they do it quite well. Most wild land/structure fires I have responded to do not start on the roof, but from inside the house such as embers entering the attic or from windows breaking from radiant heat and interior contents catching fire.
Keeping flammable materials (all types) away from the structure you are trying to defend is your best protection for the structure you are defending.
I have personally whiteness items such as plastic kids toys that were located up against a structure that caught fire and extended to the interior of the structure from a window that the toys were located under, unfortunately due to the intense winds the structure was lost.
Lots of information can be found on what your looking for, hope this helps
Great post! I was just having a conversation the other day about the amount of highly-flammable materials I have laying about. Dozens of oils and fuels and solvents and glues, etc, etc, stacked up in my garage. Some in the house.

My choices are to get rid of all of it, and let the local Lowes store it, and go get it when I need it, OR
keep it all onsite for the teaspoon or two I need every so often. Neither ideal.

Risk vs reward...
 
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