Best swimming pool heaters & accessories according to redditors

Keywords for searching are differential thermostat. Here is an example but it seems to be out of stock.

https://www.amazon.com/Differential-Temperature-Controller-Thermostat-Fahrenheit/dp/B01ETRIZUG

Buy this do this. You'll just move the display board from the old bezel to the new bezel.

Lithium-ion and lifepo have limited shelf and cycle lives, but it's still worth a shot. It will probably still work. You need to know the Ah capacity, not just the Amp output, to calculate how much energy it can store. Watt-hours = volts * amp-hours.

I guess you could shunt the excess power to heat water if you really can't find any other uses for it, but it just seems like it'd be less wasteful to charge a bigger battery bank instead (but not too big, if you're using lead-acid, because staying undercharged is bad for their chemistry; this matters less for lifepo and li-ion within like 20 to 80% charge).

What you could do instead is use the excess power for a circulating pump coupled to either a purpose-made solar thermal panel (vacuum tubes + circulating coolant) or a DIY one made with soda bottles painted black on one side. This combines the best of both worlds: the electricity circulates the water through a collector with large surface area while the sun(light) does the actual heating. Your available heat from the sun is about 1kW per square meter, so you want a water heater that's wide and flat (think kiddy lawn pool), not tall and skinny like a barrel. Now that I think about it, maybe something like an inflatable kiddy pool would be good for heating. They do make thermal-regulated pumps that only circulate the water when it's hotter on one side (the pool) than the other side (barrel), so it'll go: heat - wait - wait - wait - hot enough, circulate! - heat - heat - wait - wait - wait - hot enough, circulate! -- etc. until the whole barrel is equal to the shallow water temperature (or it gets dark and you get disappointed that you didn't just pay the 2 quarters for the campground shower).

A black plastic barrel will get warm but not hot because there's not enough surface area vs volume of the water. You have to spread the water out over an area to effectively heat it up over time, especially if you're going to be moving around and not just letting the barrel sit in a desert for a few days straight.

That will be heavy though. They do make some portable ones like this but it got very poor reviews: https://www.amazon.com/Intex-Solar-Heater-Ground-Swimming/dp/B00O80PSE6/ref=sr_1_2?ie=UTF8&qid=1468951407&sr=8-2&keywords=solar+water+heater

not sure if better ones exist.

A question about this is scale... do you mean "camping" like "I'm going to something like Burning Man where there's a lot of sun, I'll spend hours settingall it up and it'll be good for 2 weeks under direct sun" or camping like "I'm heading somewhere for a 2-day trip at the local campground, it needs to be easy to set up in 15 minutes and survive partial shade"?

Both Pentair and Hayward have great reviews on Amazon for their pumps in the $920 range:

TriStar 3202

Tristar 3200

EcoStar 3400

Pentair 011018

and with the pool servicing company doing the install the warranties will be honored for 3 years which is nice to have as well.

on a few different websites the Intelliflo comes in as the best quality but the EcoStar as the best value since it costs less to run it overall.

Do you have any other information on that?

What a neat project.

Why did you choose to build your own? I bought 2 large pool solar heaters at about $250 each (sort of like this. I could be wrong but at a glance this seems as cheap as your project if not cheaper.

What do you do for winterizing? Just drain it and leave in place?