Dishwasher

My dishes aren’t clean even with treated water – why?

Why aren't my dishes coming clean?

That’s a really good question and this discussion assumes a few things:

  • Your water treatment is the right treatment for your water problems and it is functioning/operating correctly
  • Your dishes are being washed in a modern automatic dish washer
  • Your dishwasher uses treated water

If you own a dishwasher you can relate to this: You run your dishwasher and open the door expecting sparkling clean dishes. What you actually find is something quite different, you find spots, film or white residue. You’ve got water treatment and it’s supposed to stop these problems right? All you want is clean dishes, what's going on? Is your water treatment failing, does it need service, did you buy a piece of junk or could it be something else?

Well as we said above we’re going to assume your water treatment is not the problem. Let’s examine the issue of spots, film or white residue even with treated water a bit further.

Soap related causes:

  • You are using too much soap. Try using less detergent (can’t do this with the newer soap pouches and they are not recommended). Less detergent is required with treated water and today’s more water efficient dishwashers do not use enough water to completely rinse the highly concentrated detergents available today.
  • You are using the wrong detergent. Try using a different detergent. Different detergents have different properties. Some have additives to aid in dealing with hard water problems and even iron. Some will even work to remove existing film and buildup.

Dishwasher related causes:

  • Make sure your spray arms are working correctly. They spin freely and nothing is blocking them. Inspect the spray holes and, if necessary, sse a stiff wire to clean the holes.
  • Make sure you have enough water pressure. Most washers require a minimum pressure to function properly.
  • Turn on the High Temperature Setting. Higher temperature will cause water to evaporate helping to prevent formation of deposits.
  • Improper loading of dishwasher. Often times items tall block the spray bars or large items in the lower rack prevent adequate spray from the lower spray bar.
  • Use a rinse aid. A rinse aid helps prevent water from “sticking” to the dishes therefore helping to keep whatever is causing the spots, film or residue from forming on the dishes. 

Other reasons you don't have clean dishes:

  • You are using the wrong detergent. Don’t use the dissolving detergent pods. These pods have a fixed amount of highly concentrated detergent designed to clean dishes in all kinds of water quality conditions including hard water. Problems with Pods include:
    1. You can’t adjust the amount of detergent to suit your treated water condition so you end up using too much detergent
    2. High efficiency dish washers may not use enough water during the rinse cycle to rinse the concentrated detergent off the dishes prior to drying
  • If your dishwasher is not able to completely rinse the detergent from your dishes prior to entering the drying cycle your dishes may be ruined. Here is why, let’s assume there is a detergent residue on your dishes because of an inadequate rinse. When the dishes heat up in the drying cycle they expand ever so slightly and the “pores” open allowing the detergent to enter into the material the dish is made of. After the drying cycle is complete the dishes cool closing the “pores” trapping the detergent inside the dish itself.
  • Silica may be the problem. Silica can look very similar to hard water but it is quite different and can not be fixed with a salt softener. If none of the suggestions above solve your problem(s) have your water tested for silica and treated if needed. 
  • Your dishwasher may not be using treated water. This can happen if your home was plumbed with a soft water loop. 

Good To Know

Proper dishwasher loading

Proper use of rinse aids

See Cascadian® treatment systems with PolyHalt

PolyHalt® will address both hard water and silica problems

Learn about a soft water loop

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