How To: Drain, Clean & Refill Your Hot Tub the Right Way

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Breaking news: hot tub water gets pretty gross and needs replacement more often than pools. Ok, not exactly breaking news, but it’s true, and you should know how to drain, clean and refill your spa correctly.

As a rule of thumb, you should be draining your spa every 3-4 months. You’ll know it’s time if:

  • Your spa is getting stinky
  • The water is becoming more and more difficult to maintain

Why do I need to drain so often?

Over time, salts from sweat and other non-organic materials build up in the water. These Total Dissolved Solids, or TDS, cause cloudiness or other problems.

When TDS levels get too high, the water becomes very difficult to adjust. You may have problems such as:

  • Unable to balance TA/pH
  • Excessive chemical use
  • Smelly or discolored water
  • Scale buildup at waterline

Once you have high TDS, the only recourse is to drain all (or part) of the water and refill the spa.

Pro Tip: Where water is scarce and/or expensive, draining half or three quarters of the spa and refilling with fresh water will often work to get you by until circumstances change.


Now is an excellent time to remove the filter and deep clean it with Power Soak. Just let the filter soak for an hour or so, remove it from the solution and rinse it with a garden hose.

Wait! Before you drain, make sure to clean the inside of your plumbing using System Flush. You’ll be surprised how much hidden gunk comes out of your pipes.

White hot tub with scummy biofilm floating on top of the water
You’ll be glad you got all that out of there!

Once you’re ready to actually drain the water, you’ll want to power down the spa and locate the drain. 

hot tub drain valve with yellow garden hose attached
Some manufacturers exclude a drain, or hide it in the cabinet.

No drain? Many spas come without a drain. An annoying oversight to be sure. Fortunately, we have answers for that too:

  • Electric Draining PumpThis beauty sits on the ground and sucks the water out of the spa. It also drains the spa faster than most spas equipped with a drain.
Quickly and easily drain any spa with a drain pump.
  • Shake-a-Vac II Drain WandSimple and no power cords to worry about. Simply put the wand in the water, give it a shake and stand back.
  • Good Old-Fashioned Siphon – Take a length of hose (garden hose will work) and submerge the whole thing in the spa. Put your thumb over one of the hose ends and pull it out over the edge of the spa – lower than the waterline. Boom, you’re draining.


Great, you’re halfway there. Now it’s time to grab your ecoTUB Spa Clean and Spaange and go to work cleaning the shell of the spa. Pay special attention to the waterline and remember, elbow grease is free.

Use a spray nozzle attached to your hose to wash all the cleaner into the foot well, then drain the extra water off. Don’t worry about getting every last ounce out if you’re using ecoTUB, since any extra will actually improve water quality on your fresh fill.

Now that the shell is clean and dry, it’s good practice to polish it with Gel-Gloss. In addition to restoring the luster of the shell, it cleans, seals and protects the shell. Pro Tip: for best results, apply Gel-Gloss with your Spaange.


You drained your spa because total dissolved solids were too high, so why not remove as many TDS as possible by filtering the fresh water? Here are a couple of options:

  • PreFresh A must for well water, PreFresh reduces impurities including scale, iron, staining minerals and odor causing contaminants.
  • Clarathon Disposable Hose-End Filter Economical micro-pore filter media catches sediment and particulates.

Once you’ve chosen your fill filter, attach it to the garden hose, insert it into the filter cavity and turn on the faucet. Always fill your spa in this manner to avoid air locks in the plumbing. 

Fill it up please…

Pay attention while filling the spa, you do not want to overfill it, which can cause serious damage. Fill to 2” above the highest jet (excluding neck or headrest jets).

Now you’re ready to install the filter and turn on the spa! Watch the topside keypad go through its priming cycle, noting any error codes that may appear.

Most error codes that come up during this time are due to an air lock in the plumbing. Pro Tip: Release air locks by simply loosening one of the pump unions and letting water trickle out for a few seconds.

hand touching pump union
Loosen the union until water trickles out for a few seconds to evacuate air in the plumbing.

You’re done!

Only one thing left to do: enjoy your sparkly clean hot tub!


  1. I found a thing called scum suckers that was design by an engineer in the oil fields that absorb body oil from the water in the hot tub. It works great.


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