Your Float Tank


Pumps pump, and have 2 to 3 parts – a motor, the actual pump and sometimes a strainer basket or priming chamber. They push or pump by a motor turning an impeller.


pool pump
pool pump

Pool and mag drive pumps

Pool pumps are high flow, inexpensive and have a seal. A magnetic drive pump is lower flow, more expensive, and have no seal. Both pumps should have their impellers trimmed ~10% so the motor doesn’t have to work harder than what they were designed for.

mag drive pump
mag drive pump



Do not put restrictions on their inflow ie. suction side. Both pumps need to be flooded (primed) to work. If they suck air, they stop working ie. pumping.



They clean the solution. Typical type used with float tanks are cartridge filters.


Cleaning the element

Open air release valve on filter top prior to opening filter canister to let solution drain back into the tank. Close valve prior to starting to filter again. Clean every 25 – 100 floats or by your best judgement. Replace every 10 – 40 times or when filtration action isn’t working as well. Ideally use garden hose nozzle to clean between the pleats. Spray at 45% angle and work your way down from the top.


If element is oily, soak for 2 – 8 hrs with TSP, 1cup/5gal water (3Tablespoon/gal), or 1/4liter/19liter. Rinse thoroughly. Dry in sun, if not using element right away. If seals need it, clean and coat thinly with petroleum jelly.


Saturated solution problems

Cold water doesn’t hold as much salt as warm water. So, if the solution is close to saturation at 93.5° in the tank, then in the filtration system at room temperature, at 70°, it may not hold as much salt and some of it must crystalize out. Suppose your pump holds a cup of solution, and it has to lose 1%. Then 1 teaspoon of salt will come out of solution. This typically will prevent the impeller from turning.


If salt gets crystallized in the filtration system and the pump just hums, trickle hot water very slowly through the filtration system from the suction end for 15 minutes. That should handle it. If not, try once more. Then lower the density so it does not happen again.


Hair problems

Hair can also wrap around the impeller and prevent the motor from turning. Solve by taking the pump apart and removing the hair.


Maintenance schedule 

This is typical but use your best judgement if special situations arise. Keep a maintenance log so repeat problems are solved.


Before every float

Check solution – temperature and aesthetics of solution.

Use aquarium fish net if necessary, to remove stuff floating on surface.

Disinfect solution.


Every 25 floats

Clean or replace the filter element.

Check the pH and adjust as needed (acceptable range: 7.2-7.6).

If pH becomes hard to keep balanced, check the Total Alkalinity and adjust as needed (acceptable range: 80-120 ppm)


Every 50 floats

Check the solution height and the specific gravity of the solution and add water.

Add epsom salt to reach the ideal levels (acceptable height: ≥9”, acceptable specific gravity: 1.24-1.27)

Wipe down walls with 3.5%HP.


Every 1000 floats

Use new filter cartridges (if using reusable cartridges).

If solution is becoming difficult to keep clean and clear, or it is difficult to maintain proper chemical balance, replace the entire solution in the tank.




Thermometers are not accurate. Even fever (body) thermometers aren’t generally more accurate than + – .2°C or .36°F, so 3/4°F difference between different ones. A fairly accurate high quality digital lab thermometer is a Cooper TM99. A fairly accurate glass thermometer is a Miller and Weber T-3950. It is accurate to + – 1°F. Both of these are in the $200 range. House or pool thermometers are accurate to perhaps + -5° F or more.


Adjust temperature

Stuffiness is the result of the solution being too warm for that person. Comfort range between people is about 3/4°F. If you are using a Samadhi tank, make the solution the coolest that anyone likes, and use Floater Comfort Control for those who like it warmer. Other tanks, put the temperature in the middle of the range of what people like. The range is about 93.5° to 94.5°F.



Nude body comfort range is around 72° to 90°(depending upon humidity), due to perspiration. Perspiration does a great job of cooling. If perspiration is prevented by floating in a solution & 100% humid air, the body comfort has a very small range – like one degree F.


A situation where perspiration is totally ineffective is called wet bulb temperature (air totally saturated with moisture).  From Wikipedia – humans may experience lethal hyperthermia when the web-bulb temperature is sustained above 35°C (95°F) for six hours. As of 2010, wet-bulb temperatures only very rarely exceeded 30°C (86°F)anywhere on planet Earth.


The point here is do not put solution temperature above people’s comfort range. If people think the solution is too hot, lower it.



Disinfection (not sterilization)


Run ozonator (corona discharge type) 25 minutes between floats OR use 35% Hydrogen Peroxide (start with .5 tsp or 2.5 ml) at the end of the day to make the solution 30-50ppm. It can be helpful in addition to use a thin film UV system.  To test for the presence of HP residual, use La Molla #2984 HP test strips. All forms of disinfection create a small amount of a reddish brown precipitate. Filter whenever disinfecting.


Lab tests

Use lab test to insure your maintenance is successful in disinfecting the solution properly. Test for Heterotropic Plate Count and Total Coloform. Results of HPC should be less than 200CFU (Colony Forming Units) and the Total Coloform results should be absent.


Taking sample 

Get sample bottles from lab. You don’t need the ones that have something in them to neutralize chlorine, since you aren’t using it. Take sample below the surface and put the cap back under the surface. To find a lab, search the internet for Environmental Laboratory Accreditation Program labs that are local to you.




Use great care in handling these dangerous chemicals.


Testing pH

Keep pH in the right range by testing with a digital pH test meter. HM Digital  HMDPH200 Waterproof pH and temperature meter seems to be good. NOTE:  digital pH meters must have their tip kept wet and be calibrated monthly. Be sure to buy storage solution and 7.0 calibration solution when you buy the meter.


Adjusting pH

Neutral is 7.0 pH, acid is 0 to 7.0 and base or alkaline is 7.0 to 14. Ideal is 7.2 – 7.6.

If too low, add (dry powdered) sodium carbonate.

If too high, add (dry granular) sodium bisulfate.


Add 1 Tablespoon (15 ml)  of the material to a cup (1/4 l) of water, not the water to the material. Then add to the tank and run the filter for 5 minutes. Retest and repeat until it is in the right range.


Total alkalinity

Needs to be in the right range of 80 – 110, or the pH will fluctuate too much. Test with Hach # 2744850 Total Alkalinity test strips 0-240mg/L.

To raise, add 1 Tablespoon ( 15 ml) sodium bicarbonate, ie. baking soda, to the tank solution.

To lower, add 1 Tablespoon (15 ml) sodium bisulfate add to a cup (1/4 l) of water, then add to tank solution.

Filter 5 minutes, test and repeat until correct.


Replacing the solution

If it seems difficult to keep the solution balanced and clean, it may need to be replaced. It may be pumped down a sewer without a problem. It should not be put in a septic tank, but put in containers to evaporate. Generally, due to the problem of a vortex resulting in air breaking the prime of the pump, it is easier to use a sump pump. Any will work, that don’t drip oil, as long as they are used for short periods of time and rinsed thoroughly after use.


When salt recrystallizes

It does so in a very sharp form that can easily hurt people and puncture vinyl liners.


Adding Salt

There is about 150 gallons of solution in a Samadhi tank. So you may be able to judge yours from that. If you add 750 lbs at the beginning and that results in a specific gravity of 1.25 or 1.250, then the salt is at 25%. So, if 750 lbs equals 25% then 750/25 is 30 lbs equals 1%. If you want to move the specific gravity up from 1.230 to 1.260, then you want to move it up 3% or 3 X 30 or 90 lbs.


(In metric that is, if 350Kg is 25%, then 14Kg is 1%. So to move the specific gravity up from 1.23 to 1.26 then you are moving it up 3%. So to raise the density up 3%, 3 X 14 is 42, so add 42 Kg.)


Solution problems

Bubbles and scum floating on the surface of the solution can be created if people go into the float tank with oils on their skin. Use an enzyme product like Natural Chemistry’s Pool Perfect. Use .5 Tablespoon of it and filter, not right after adding a disinfectant like HP. Repeat until the problem is handled. You may have to clean the filter more frequently with this situation.


If there are problems with the smell or look of the solution and the tests indicate it is balanced, first add 2-4 oz of hydrogen peroxide and filter for a couple hours. If doing this twice doesn’t handle it and the filter has not been cleaned recently, clean it and filter a few hours more.



As a safety measure, the tank should be electrically grounded. Also, it is possible that the heater will create an induced current if a person touches the solution and grounds themselves by standing on a floor or shower base that is grounded. To ground the solution, put a stainless steel nipple, 4 times as long as it’s diameter, in the plumbing of the filtration system.


Grounding the wire

Attach a grounding clamp to the stainless pipe and a 12 gauge stranded wire to clamp and ground the other end. It is easiest to ground it by plugging it into the ground part of a grounded receptacle.


If your receptacles are not grounded, attach the ground wire to a metal water pipe.  The grounding clamp for  1.5″ pipe is LH Dottie #27 or Eritech CWP2JU and for 1″ is LH Dottie #20 or Eritech CWP1JU.