Is my cell dying?

[JimK]

Update...

As I mentioned yesterday, I increased the SWCG to 65%. I tested again this evening and the CL level increased by .5 ppm. So the cell is working, although I'm having to set it at a higher level than when it was new. I turned it down slightly to 63% to see if CL levels off.

I know the manual says only to acid wash if scaling is severe, but I'm wondering if an acid wash might help it work more efficiently? I did find one post where their salt reading was incorrectly low and an acid wash corrected the issue. I've never acid washed it before (again, it was installed in June 2008). Might I harm the cell or shorten its life by doing an acid wash?

[mas985]

Definitely, I would try acid cleaning. I am surprised you went this long without an acid clean. That is usually the first thing I do when I detect a decrease in cell output. Manual cleaning only gets the deposits you can see which is basically the ends of the cell. The internals are not easily cleaned manually.

Also, I clean my cell with acid several times during the season and the cell is over 7 years old and still going strong. I don't use full strength (1:4) and just long enough until all the fizzing stops.

[JimK]

Definitely, I would try acid cleaning. I am surprised you went this long without an acid clean. That is usually the first thing I do when I detect a decrease in cell output. Manual cleaning only gets the deposits you can see which is basically the ends of the cell. The internals are not easily cleaned manually.

Also, I clean my cell with acid several times during the season and the cell is over 7 years old and still going strong. I don't use full strength (1:4) and just long enough until all the fizzing stops.

Thanks. That gives me the confidence to try an acid cleaning. I was hesitant before because the manual had me thinking that acid washing could harm the cell, hence the instruction to only use acid if scaling was "severe".

I do need to order a cleaning stand so I don't have to immerse the cell into a bucket.

So the solution you use is one part muriatic acid with 4 parts water?

[mas985]

So the solution you use is one part muriatic acid with 4 parts water?

Correct.

[JimK]

Correct.

Thanks.

How do I safely dispose of the acid solution when I'm done?

[mas985]

Probably the safest place is back in the pool. You would be adding CH back to the pool but it is probably small compared to what is already in the pool. Just keep track of how much acid is in the solution so you don't add back too much at once. Basically your normal dosing. I clean my cell in a dosing bucket so I just use it for dosing at a later time.

Otherwise, you would have to dilute it further and perhaps neutralize it before disposing in a drain.

[BigDave]

Remember (9th grade chem) when diluting acid, you put acid into water (A->W). Never water into acid. Wear goggles, gloves, avoid the fumes, have a plan for if it spills.

I'm sure you know all this already, but if not... See Using Muriatic Acid to Safely Lower Your Pool's pH.

[JimK]

Probably the safest place is back in the pool. You would be adding CH back to the pool but it is probably small compared to what is already in the pool. Just keep track of how much acid is in the solution so you don't add back too much at once. Basically your normal dosing. I clean my cell in a dosing bucket so I just use it for dosing at a later time.

Otherwise, you would have to dilute it further and perhaps neutralize it before disposing in a drain.

Thanks for the tips.

Since I'll be using a cleaning stand and just filling the cell with the acid solution (as apposed to soaking the cell in a bucket), I expect I won't be using that much acid. However, I'd prefer not to add CH back into the pool if possible. I'm hoping to let it drop this year. At closing last year CH was at about 250 ppm. This will be my first season not adding anything with calcium, ie - I use to use Cal Hypo to shock, this year it will be strickly plain bleach to shock when needed.

This will be the first time I've done this, so I'm trying to be prepaired to avoid any unpleasant surprises.

Tips and suggestions are most welcome.

[JimK]

Update...

As I mentioned yesterday, I increased the SWCG to 65%. I tested again this evening and the CL level increased by .5 ppm. So the cell is working, although I'm having to set it at a higher level than when it was new. I turned it down slightly to 63% to see if CL levels off.....

At 63%, CL was still increasing, so yesterday I dropped it to 55%. It's apparent the cell is still working. Hopefully it won't give out any time soon.