Residue on side of the tub?

[fuzzybeekeeper]

I have a lot of rough residue that is attaching itself to the side of my tub.  I have my own water well in the country and am not on city water.  It takes about three days for the sides to get rough and now it feels like sandpaper when you sit on it.

It is fairly easy to get off with a scouring pad and elbow grease, but it is a real pain, both to remove and as you sit on it.

I know it is something in my water but I have no idea what it is.  We have had the tub for 4 years and this has just started.  My water supply has not changed.  I think it may be calcium from the water.  What can I do to keep this from happening?  What can I use to get this stuff off the sides without spending 5 hours scrubbing?

Fuzzybeekeeper

[wmccall]

Since you suspect calcium, have you measured the hardness of the water?

[hottubdan]

Most likely it is calcium precipitating out of the water from high pH.

Lower pH.

When you drain use some white vinegar to help dissolve it if it has not come off over time.

[stuart]

If I had to guess I would say it's calcium...I've seen it a lot when people are using cheap Chemicals like HTH or anything that uses Cal-Hypo as the medium

[fuzzybeekeeper]

Ok, I thought about vinegar since I add it to our dishwasher to keep our glassware clear.

Would it work to add 4 or 5 gallons (or more... vinegar is cheap) to the tub before I drain it and let it sit for a day or two to disolve what is on the side of the tub?

Will vinegar ruin the finish on the fiberglass (if that is what a tub is made from)?

Thanks.

Fuzzybeekeeper

[ndabunka]

Correct me if I am wrong but calcium would STILL be in the water even after adding vinegar, right? Wouldn't the best solution simply be a drain and re-fill and then be more careful about the chemicals you use?  If you haven't done a refill in a year, you need to do it anyway, right?

[fuzzybeekeeper]

Yes, the calcium would still be there, but I thought the vinegar would change the chemical composition and let it be "suspended" or become solid in the water.

Does anyone know if such a mild solution (10 gallons of 9% vinegar in ? 500 ? gallons of water) would dull the finish?

And would it even begin to REMOVE the residue (depending on what it is, of course) from the side of the tub?

Fuzzybeekeeper

[Dr. Spa™ Ret.]

vinegar would simply make the water more acidic, which would retard the precipitation of the calcium. The acidity though would have other negative effects on the tub and equipment.