Dumping and refilling the spa weekly versus just balancing it like the pool

Started by Karen Delgado · · 2 replies
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#1
Been going back and forth on this all summer. Spa's plumbed to the same pad as the pool but I run it separate chemistry wise since it heats up and evaporates faster. Right now I just dose it like a mini pool, test it on its own, adjust as needed. Thinking about just draining and refilling it weekly instead since it's only a few hundred gallons and fill water is the problem child here anyway at 400 plus calcium straight out of the hose.

Draining weekly means fighting that high CH from scratch every time. Balancing it means I'm constantly chasing numbers in a smaller body of water that swings fast with heat. Anybody actually crunched which costs more, the water or the chemicals. My service doesn't touch the spa so this is all on me.

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#2
Our spa is plumbed separate from the pool too and I went through this exact debate last summer, ended up just balancing it like a tiny pool instead of draining because with three kids using it most nights the fill water fight felt worse than just chasing numbers. Your 400 plus calcium out of the hose is rough though, mine's not that high and I still notice it creep after a refill, so if I was starting from that every week id go broke on calcium reducer or just accept scale forming. I say balance it and only drain when it actually gets gross or the CYA creeps up from bather load, which with a small volume happens fast anyway so you sort of get a natural refresh every month or so without fighting the hose water from zero every single week.
#3
My pool and spa share the same water since mine's plumbed as one body with a spillway, so I don't deal with this at all, but that 400 plus CH out of the hose number caught my eye because mine tests around 180 and I still see it climb into the 300s by mid summer just from evaporation concentrating it. If you're starting at 400 before any evaporation does its thing, a few weeks of running the spa hot every night and you're probably flirting with scale territory regardless of which method you pick. Not solving anything for you, just saying your fill water is rough enough that the math might not even be close.