Walk into any pool store and you’ll see two full aisles of spa chemicals, most of which you don’t need. In practice, a well-run hot tub needs a short, boring list of products used on a predictable schedule — not a shelf full of specialty bottles. Here’s our current pick in every category, plus a realistic sense of how often each one actually needs replacing.
Our picks
AquaChek Select Connect 7-Way
Reliable, easy to read, and covers every parameter SpaCheckup tracks — the one product every routine starts with.
View on Amazon →Clorox Pool&Spa pH Down
The workhorse of spa care — hot, aerated water almost always drifts pH upward, so this is the bottle you’ll reach for most.
View on Amazon →SpaGuard Total Alkalinity Increaser
Buffers pH so it stops bouncing around — usually the real fix when pH won’t hold no matter how much you add.
View on Amazon →Leisure Time Spa 56 Chlorinating Granules
Fast-dissolving chlorine made for spas, at 56% strength — pairs directly with the app’s product-strength setting.
View on Amazon →Clorox Pool&Spa Bromine Tablets
Gentler smell and more stable in hot water than chlorine — the standard pick if you’ve gone with a bromine spa.
View on Amazon →SpaChoice 1-Pound Premium Bromine Booster
Sodium bromide — the one-time dose that builds a fresh fill’s bromide reserve before tablets have anything to work with.
View on Amazon →SpaGuard Spa Water Clarifier
For the stubborn haze that remains after your chemistry is already balanced — a situational buy, not a weekly one.
View on Amazon →Leisure Time Renew Non-Chlorine Shock
32% potassium monopersulfate (MPS), no chlorine in it. Chlorine tubs: burns off the chloramines behind that “chloriney” smell without adding chlorine or CYA. Bromine tubs: this is what converts your bromide reserve into active bromine. Either way it is an oxidizer, not your sanitizer — check the label says non-chlorine, since several similarly-named “spa shock” products are actually dichlor.
View on Amazon →SpaGuard Spa Calcium Hardness Increaser
Protects your heater and seals from aggressive, calcium-hungry water — typically a once-per-fill dose, not a recurring buy.
View on Amazon →Leisure Time Spa Cover Care and Conditioner
Keeps the seal tight and stops mold before it starts on the underside, where it grows first. Not a water chemical, but earns its spot.
View on Amazon →Scumbug Hot Tub Scum Absorber (2-Pack)
Floats in the water and soaks up body oils before they concentrate into a waterline ring. Rinse and reuse all season — prevention, not a cure for a ring that's already there.
View on Amazon →Superior Pump 91250 Submersible Utility Pump
Turns a 2+ hour gravity drain into about 20 minutes. Not spa-branded, and doesn't need to be — it's the same pump people use for a flooded basement.
View on Amazon →As an Amazon Associate, SpaCheckup earns from qualifying purchases. We only recommend products we’d use in our own spa.
How often you’ll actually buy each one
This is the part most lists skip, and it’s the difference between a full cart and a wasted one. Only a couple of these are true recurring purchases — most are a once-per-fill or as-needed item:
| Product | Category | How often | Price tier |
|---|---|---|---|
| AquaChek Select Connect 7-Way | Test strips | Every 1–2 months | $$ |
| Clorox Pool&Spa pH Down | pH control | Every 1–2 months | $ |
| SpaGuard Total Alkalinity Increaser | Alkalinity | Once per fill (~3–4 months) | $ |
| Leisure Time Spa 56 Granules | Chlorine sanitizer | Every 1–2 months | $$ |
| Clorox Pool&Spa Bromine Tablets | Bromine sanitizer | Every 1–2 months | $$ |
| SpaChoice Premium Bromine Booster | Bromine booster | Once per fill (bromine only) | $ |
| SpaGuard Spa Water Clarifier | Water clarity | As needed | $ |
| Leisure Time Renew Non-Chlorine Shock | Shock (non-chlorine MPS) | Monthly, more after heavy use | $$ |
| SpaGuard Calcium Hardness Increaser | Calcium hardness | Once per fill | $ |
| Leisure Time Cover Care and Conditioner | Cover care | Every 3–4 months | $ |
| Scumbug Hot Tub Scum Absorber | Scum control | Ongoing, reusable all season | $ |
| Superior Pump 91250 | Drain equipment | One-time buy | $$ |
What to actually buy first
If you’re stocking a hot tub for the first time, you don’t need one of everything on day one. Start with test strips, your sanitizer of choice, and pH decreaser — that trio handles the vast majority of a normal week. Alkalinity and calcium hardness increaser only matter once you’ve tested your actual fill water and know where it stands; buy them reactively, not preemptively. If you’ve gone with bromine, add a bromine booster to that first cart too — it’s the one-time dose that builds the reserve a fresh fill doesn’t have yet, and tablets alone can’t make up for skipping it. Shock, clarifier, and cover care round things out once you’re a few weeks in and have a feel for your routine. The full breakdown of what each reading means and how the five numbers interact is in the complete hot tub water care guide.
Bought it — now dose it exactly
SpaCheckup already knows the product strength for dichlor, calcium chloride, liquid chlorine, and MPS shock — pick what you bought and it tells you the exact amount, sized to your spa.
No more guessing at the dose
SpaCheckup turns your test-strip readings into exact amounts to add — matched to your spa’s volume, sanitizer, and whichever product strength you bought.
Free to download — unlock everything once. No subscription, no ads.
Frequently asked questions
Do I need all of these hot tub chemicals?
What chemicals does a new hot tub need first?
Can I use pool chemicals in a hot tub?
How often do I need to buy hot tub shock?
Do I need a bromine booster if I already have bromine tablets?
Related guides
Hot tub water care: the complete guide
The five numbers that matter, their target ranges, and exactly how to fix each one — the whole picture in one place.
Read the complete guide → BasicsHow to shock a hot tub (and when)
What shocking actually does, chlorine vs. non-chlorine shock, how much to add, and how soon you can soak again.
Read the guide → DecisionsChlorine vs. bromine — which should you use?
An honest comparison of cost, maintenance effort, and feel, and how to switch if you change your mind.
Read the guide →