Rainbow effect on glassware in dishwasher? Could be Soft water?

[Kamisn]

Hi all, I am getting rainbow effect and haze on glassware after dishwasher is done. This has started maybe in past 6-8 months and at first I thought its because of couple of old dishes but now all glasswares have the effect. I tried forums and other websites and the answers are not conclusive.

Somehow I am suspicious this might have something to do with my water softner, water quality and dish soap I use.

I use Potassium in the softener due to skin irritation with salt, I have a 48000 grain softener with Clack valve that is less than two years old, the unit regenerates every 2 weeks or 2200 gallons with 11 lb of potassium with "pre" soaking of the salt due to using the potassium (got the advise from senior member of the forum couple of years ago). The water feels soft and droplet test also confirms the softness.

I use Cascade platinum and Finish Jet Dry in the dishwasher with heated dry settings, dishwasher is GE Monograme.

Do you guys see any issues with above setup that could cause this?

Thanks for the help!

 

[Reach4]

Did you maybe change to a different kind of light in the kitchen? Maybe a different spectrum.

Rainbow would be thin film interference, and I would have thought that would be while the glassware is wet. Do you get that while dry?
https://www.explainthatstuff.com/thin-film-interference.html

Maybe try running an extra rinse, or even a second wash with no Cascade.

Nice you are getting the ~2 weeks of softening per regen.

 

[Sponsor]

 

[Bannerman]

You really haven't told us much.

What is the water hardness? 11 lbs potassium chloride does not seem sufficient to provide 2200 gallons unless the raw water hardness is low.
Is your water source municipal or private well?
List all of the cycle settings programmed on the softener.

Cascade Platinum is a pre-measured soft pod dose. I find pre-measured DW and laundry detergent quantities are too large for softened water as they are sized for water that contains some hardness. When the detergent amount is too high, the dishes, particularly glassware will become etched which maybe starting to occur.

There had been some DW detergent brands that were offering hard pucks or bricks which I was cutting in half as I found only 1/2 of the pre-measured amount was the correct quantity. I no longer see those detergent pucks/bricks sold and as soft pods cannot be cut in two, I now purchase Cascade DW powder and only fill 3/4 of one dispenser cup with detergent in our GE DW. With two people, a large box of DW powder will last us more than 6-months.

 

[Kamisn]

Did you maybe change to a different kind of light in the kitchen? Maybe a different spectrum.

Rainbow would be thin film interference, and I would have thought that would be while the glassware is wet. Do you get that while dry?
https://www.explainthatstuff.com/thin-film-interference.html

Maybe try running an extra rinse, or even a second wash with no Cascade.

Nice you are getting the ~2 weeks of softening per regen.

No light change, the film is there on dry surfaces.

 

[Kamisn]

You really haven't told us much.

When the detergent amount is too high, the dishes, particularly glassware will become etched which maybe starting to occur.

I think that's exactly what's happening to mine.

The clack I have is the 5 button one so it doesn't show the details on the valve but I am using C-9. I used to put 9.5 lb of salt to regenerate and when switched to Potassium I raised the amount by suggested 15%, and that's how I came up with 11lb. The water is municipal and the hardness is around 9-11.

 

[ditttohead]

A little experiment. Turn off the heat dry feature. Try using half the soap that is recommended.

 

[DIYMissus]

A water test is needed, in the meantime after the DW finishes its Cycle throw about a cup of cleaning vinegar (2x strength white vinegar ) in and run it on rinse only cycle. If it is typical hardness issue that should help.