My aerator

[chem geek]

Roohollah,

Welcome to TFP!

The aeration does increase the rate of carbon dioxide outgassing and therefore the rate of pH rise, but that is intentional and done in conjunction with adding acid in order to lower the Total Alkalinity (TA). It is a process to Lower Total Alkalinity that includes keeping the pH lower since that too increases the rate of carbon dioxide outgassing. Think of pools as being over-carbonated. If you vigorously stir a carbonated beverage, you make it go flat faster. If you were to add acid to it (such as adding vinegar to baking soda) it will bubble more. The same concept applies to swimming pools. 25-1/2 fluid ounces of full-strength Muriatic Acid (31.45% Hydrochloric Acid) in 10,000 gallons lowers the TA by 10 ppm no matter how you add it. It also lowers the pH so to get the pH to rise without raising the TA requires forcing carbon dioxide out of the water into the air. By the way, we recommend using Muriatic Acid instead of dry acid in order to avoid a build-up of sulfates that at high levels can be damaging to plaster.

Richard

 

[domogala]

A huge thanks to Rangeball for the base design and inspiration to build my own. I really didn't know how I was gonna aerate the water to get the pH back up after adding the MA.

Here's some photos of my aerator:

The two nozzles at the ends have 45 degree elbows so the spray from them does not get too close to the pool wall. Each nozzle is pointing down 45 degrees.

Here's a closeup of one of the nozzles, made from a 1.5" PVC cap:

I used a PVC union to make it easier to turn the threaded section into the return without the entire assembly attached to it. It also makes it easy to adjust the rotational position.

The smaller half of the union is attached to the return adapter. This is nice for tightening.

The unit is attached to the return, adjusted and the union tightened.

The device in action! It really churns up the water.

Parts list (all 1.5" schedule 40 PVC):
3 caps
1 cross
5 45 degree elbows
2 90 degree elbows
1 union
1 1.5" male adapter
4 ft pipe (for the riser and pieces between the fittings)

I glued the adapter union and riser elbow together. The rest of it is friction fit.

 

[domogala]

Here's what happened overnight with the second dose of MA... The aerator ran from 10PM until 10AM this morning. So after 12 hours the TA was 100 (was 130 just before ading MA) and the pH was 7.5 (no idea how low it went with the addition of MA, but it was 7.8 just before the MA was added). I disconnected the aerator at that point. I'll let the pool run normally until Saturday and check everything again. If all is well I may close the pool for the winter. Here in southern NH it's already getting cool enough to do so.

Thanks for such a great site!!

 

[Roohollah]

Dear Mr.Richard ,
Thank you for your scientific and very beneficial answer .It helped me to understand the process of the PH.We appreciate that taking the time to teach us to do our job better and we improve our knowledge by your brilliant web site.

Yours Faithfully,

Your new student,

Roohollah

 

[allanby]

You guys seem to know your stuff much more than the "professionals" over here in tropical Thailand.

I have the same problem with low PH (6.4) and high TA (180+) which has changed only a little since I filled the pool, so the tap water wasn't that balanced to begin with. I have heard that an Aerator will solve both these problems and will make one to screw into one of my 3 pool outlets.

Initially I plan on addressing this along with another problem, the pool water is too cold (26C) and am making a simple solar heater. I have a roof on my pool, which keeps the water cool here during the long hot summers, which will keep the chlorine working, but with an unusually cool period, thought I would warm things up a bit now.

So my short term plan is this.

Drop a 1/3hp submersible pump in the pool and run 30 metres of dark plastic tubing onto the roof (heating the water) and then dropping this water the 2 metres into the pool water, via a 1 micron bag filter, with a chlorine tablet in.

Essentially, heating, chlorinating, aerating and polishing the water in one go.

What do you think? Should I expect to lower the TA and raise the PH by doing this?

Thanks

 

[Bama Rambler]

The aeration should raise the pH and then as you add acid to bring it back down it will lower the TA as well. That should work. 30m of I'm afraid won't do nearly as much to heat your pool as you might think. Also adding the puck will lower your pH which is exactly the opposite of what you want to do. Since the puck is acidic it'll most likely attack the filter bag shortly and ruin it.

Do you know what your CYA is?

 

[pcmacd]

Surely would like to see a pitcher of this?

tanks