How to Drain and Refill Your Hot Tub

♻️ Time for a Spa Refill?  First Run a Flush to Clean Out the Gunk You Can’t See

You've enjoyed you spa for a few months now, but for some reason your water is eating up chemicals and it has become harder to balance. Most likely you’re due to drain the tub and start over!

How can I tell it's time to drain and refill?

There is no single indicator, but generally you will notice a few of theses symptoms:

• Your TDS is over 1500 above its starting point.
• The water no longer will clear as well as it did in the beginning.
• You are getting a lot of foaming that is not going away with Enzymes or keeps returning.
• You are noticing more chemicals are needed than in the past.

🛠️ I need to drain and refill...What are the steps?

Note: Do not drain any brand of spa during freezing temperatures, as there will still be some water remaining in the lines after draining.  These are generally the smallest lines and therefore the easiest to freeze.  If you are not planning to use your spa over the winter, be sure to have it properly winterized, not just drained.

Spas with Spaboy:

If you own an Arctic Spa and have Spa Boy installed, remove the grate over your probe and thread on the probe cap. Directions on the Spa Boy probe can be found here: Spa Boy Probe Plug Directions ; Spa Boy Probe Installation Directions. 

🧪 Step 1 - Flush out the Plumbing

What Is Spa System Flush?

Over time, your hot tub’s plumbing builds up biofilm — a slimy layer of bacteria, organics, and other contaminants that can reduce sanitizer effectiveness and cause cloudy water or funky smells.  The spa flush will loosen up any biofilm debris in the plumbing.  Biofilm can affect chlorine levels negatively when trying to balance water. Biofilm builds up whenever you are using the tub; this film comes from oils and other organic materials bathers bring into the water.  

System Flush is an earth-friendly, non-toxic cleaning solution that removes biofilm and organic residue from your spa’s plumbing system — without the use of soaps, detergents, or alcohol.  It targets hidden build-up in jets, lines, and internal surfaces to restore clean water flow and maintain optimal performance.

✔️ Safe for use in hot tubs, whirlpools, and fountains
♻️ Biodegradable & gentle on surfaces
🔁 Designed for use prior to draining

Premier Pool & Spa carries a few brands of Spa Flush.  We have tested all of these both in our store and in the field, and can recommend them all.  

• Hot Tub Serum
• Ahh! Some Jet Cleaner
• SeaKlear Spa Flush

 How to Perform a System Flush: Step-by-Step

• Remove filters, scum balls or other floating items, and spa cover

• Leave water at a warm to normal operating temperature (won't work as well in cold water)

• Ensure all jets and diverters are open for circulation through all plumbing

• Add the recommended dosage of your preferred Spa Flush

• Expect heavy foaming — that’s the biofilm being released

• Let circulate for a minimum of 1/2 hour, and for best results up to 12–24 hours, running jets on high as much as possible

⚠️ If your tub is indoors, prepare for foam control to avoid spills or overflows

🚿 Step 2 - Drain the Old Water

Before removing water from the tub, make sure the power to the tub is turned off. 

Once turned off, use a submersible pump to remove water or use the drain built into the tub. Using a submersible pump will speed up the process.  

If you prefer to use the drain on the spa (slower), here are the directions:

🧼Step 3 - Wipe Down the Shell

• As the spa drains, wipe down the shell to remove residue

• Use remaining spa flush liquid for stubborn grime

The system flush products are meant to get the biofilm debris out of the plumbing.  When the debris detaches, it will re-collect on the shell surface. To remove it, blend a mixture of 25% vinegar and 75% water in a spray bottle. Spray the shell down and wipe mixture and debris away with a microfiber cloth. Rinse the shell off with water from your hose.

Step 4. Clean Your Filters

• Make sure to have a second set of filters so you can replace the existing set while the first set is being cleaned and dried.

• Spray filters with a hose to remove large debris

• Soak in a spa filter cleaner + hot water solution for 24 hours

• Rinse thoroughly and dry before reinstalling

💧 Step 5 - Refill & Rebalance

• Make sure your drain valve is closed if you opened it to drain the spa. 
• Fill the spa through the area where the filter(s) install.

• Refill with fresh water using a Pre-Filter to remove metals from your water while filling.

• Test water and balance chemicals (pH, alkalinity, sanitizer)

Once you have filled the tub, you can reinstall the filter(s), switch the power to the spa back on and begin to heat to your desired temperature.

Occasionally you may encounter an air lock on your spa pump, every spa is susceptible to this, but it is generally easy to fix by following the directions in this video: https://youtu.be/iVJdPVViM3o?si=G0x89DIYZQ7QNqYI