Quick Answer: Neither brand is better across the board. Compare the matching product lines, not the logos. For plain, additive-free pellets, Diamond Crystal Bright & Soft wins because Diamond Crystal publishes a typical purity figure (99.8%) and Morton doesn't. If you want a pellet with an anti-buildup additive, Morton Clean and Protect is the one to buy, because Diamond Crystal's plain pellet has no equivalent. With iron in your water, both brands' iron formulas are reasonable. Buy whichever you can get reliably, and don't switch back and forth every month.
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| What you need | Diamond Crystal | Morton | Edge |
|---|---|---|---|
| Plain pellet | Bright & Soft, typical 99.8% purity, no additive | No plain pellet on Morton's current lineup page | Diamond Crystal |
| Pellet with cleaning additive | No direct match | Clean and Protect | Morton |
| Iron formula | Iron Fighter: pellets, crystals, blocks, cubes | Rust Defense: pellets | Diamond Crystal, for more choice of forms |
| Crystals | Solar Naturals, typical 99.6% | Pure and Natural, "high-purity" (no figure given) | Tie in practice |
| Potassium chloride | K-Life | Potassium Chloride Pellets, marketed as 99% sodium-free | Tie |
If you just want one bag: Plain water and any softener: Diamond Crystal Bright & Soft. A brine tank that keeps growing crud: Morton Clean and Protect. Iron in the water: either brand's iron formula, plus the reality check in the iron section below.
In this guide
- Why "which brand?" is mostly the wrong question
- Purity: one brand shows its numbers, the other mostly doesn't
- Morton's additive, explained without the marketing
- Iron Fighter vs Rust Defense: helpful, but only up to a point
- Crystals: closer than any other match-up
- Potassium chloride: same idea, same trade-offs
- Blocks and cubes: only Diamond Crystal makes them
- Switching brands won't hurt, but do it once
- So which bag goes in your cart?
Why "which brand?" is mostly the wrong question
Your softener doesn't know which logo was on the bag. It needs a steady supply of brine that's mostly sodium chloride, without much insoluble grit. Both companies make that. The trouble starts when the salt's form doesn't suit your tank, or when the bag carries an additive you didn't need or didn't know about.
So the useful comparison is line by line: Diamond Crystal's plain pellet against Morton's pellet, crystals against crystals, iron formula against iron formula. We put this together from each brand's current product pages, how each line is described, and what each one is meant to fix. We didn't run any tank-side tests.
Purity: one brand shows its numbers, the other mostly doesn't
Diamond Crystal publishes a typical purity on each product page:
- Bright & Soft pellets: typically 99.8%
- Hardi-Cube: typically 99.7%
- Solar Naturals and Sun Gems crystals: typically 99.6%
Morton's water softener salt page doesn't give a percentage for its sodium chloride lines. Pure and Natural crystals are described only as "high-purity," and the potassium pellets are marketed as 99% sodium-free.
Does 0.2% matter? It can. The non-salt part is mostly insoluble material, and it doesn't dissolve. It settles at the bottom of the brine tank as a layer of sludge. Using very roughly 10 lb of salt a week (the real figure depends on your hardness and settings, so see how much salt a softener uses), the gap between 99.8% and 99.6% works out to around a pound of extra residue a year. It's not dramatic, but it adds up between cleanings. It matters most in a cramped cabinet softener.
That's the main reason Bright & Soft gets our nod as the default plain pellet: you know what you're getting.
Morton's additive, explained without the marketing
Morton's main pellet, Clean and Protect, has an added ingredient that Morton says reduces buildup, makes cleaning easier and helps extend appliance life. Morton doesn't say on that page exactly what the additive is.
Who that suits:
- People with an older or neglected brine tank who'd like the salt to help keep it cleaner
- Anyone who has had trouble with salt bridges or sludge and wants to try something different
Who should skip it:
- People who want nothing in their brine except salt. Diamond Crystal Bright & Soft is the plain option.
- Anyone whose softener manual says anything about salt type. Check yours before switching, and follow it.
Bright & Soft: typical 99.8% purity, greater than 99.7% water soluble, no additive. The linked listing is two 40 lb bags. Good for most softeners, well or city water, as long as there's no meaningful iron. Downside: in some areas it's harder to find on store shelves than Morton. Check price on Amazon
Clean and Protect: evaporated salt pellet with Morton's anti-buildup additive. The linked listing is two 40 lb bags. Good for cabinet softeners and tanks that collect crud. Downside: the additive isn't fully explained, and the purity isn't stated. Check price on Amazon
Iron Fighter vs Rust Defense: helpful, but only up to a point
Both brands sell an iron formula. Diamond Crystal sells Iron Fighter in more forms than Morton: pellets, Sun Gems crystals, blocks and a Hardi-Cube "Red·Out" version. Morton's Clean and Protect Plus Rust Defense comes as pellets only, and Morton says it targets rust stains and improves taste.
What neither bag will tell you: an iron salt helps a softener clean small amounts of iron off the resin during each regeneration. It doesn't turn your softener into an iron filter. Once dissolved iron goes above about 1 ppm, the usual advice is to install a dedicated iron filter ahead of the softener. Iron salt alone won't keep up. Our guide on whether a softener can remove iron explains where that line sits.
How to choose between them:
- You need crystals or blocks, for example a two-tank system or a softener that takes block salt: Diamond Crystal, because Morton doesn't offer its iron formula in those forms.
- You already use Morton pellets and just want rust control: Rust Defense is a straightforward switch.
- You have no iron: skip both. You'd be paying for an additive that has nothing to do.
Iron Fighter pellets on Amazon (3 × 40 lb) · Rust Defense pellets on Amazon (third-party seller; check the bag photo before ordering)
Crystals: closer than any other match-up
If you run a traditional two-tank softener with a tall, open brine tank, crystals are often the better value. Here the brands are nearly interchangeable. Solar Naturals has a published typical purity of 99.6%. Morton Pure and Natural is described as high-purity but has no figure. Buy whichever is cheaper and easier to get.
Crystals have one real limitation: in a short cabinet softener, irregular crystals can pack together. If your softener is a single cabinet with a salt lid on top, stick with pellets from either brand.
Solar Naturals on Amazon · Pure and Natural on Amazon (4 × 40 lb)
Potassium chloride: same idea, same trade-offs
Both brands sell potassium chloride for people who want to cut back on added sodium: Diamond Crystal K-Life and Morton Potassium Chloride Pellets. The trade-offs are the same whichever you buy. It costs more per bag than sodium chloride, and it usually needs a higher salt-dose setting to do the same softening work. If you switch, change the setting too. Our guide on setting the salt dose shows where that setting lives on common valves.
Neither brand's potassium bags had a reliable in-stock Amazon listing when we last checked, so we haven't linked them here. Hardware stores that carry softener salt usually stock at least one of the two.
Blocks and cubes: only Diamond Crystal makes them
Diamond Crystal's lineup is wider than Morton's. Besides pellets and crystals, it makes Bright & Soft blocks (typical 99.8%), Iron Fighter blocks, Hardi-Cube compacted cubes (typical 99.7%) and a Hardi-Cube Red·Out version with the Iron Fighter formula. Morton's current water softener salt page lists only pellets and crystals, all in 40 lb bags.
That only matters if your softener calls for blocks or cubes. If it does, the brand choice is made for you. If it doesn't, ignore these. Loose pellets or crystals are what nearly every home softener is designed to use.
Switching brands won't hurt, but do it once
Changing from Morton to Diamond Crystal, or the other way, is fine. Problems usually come from switching forms (crystals on top of pellets, or blocks mixed with loose salt), or from piling new salt on a hard crust of the old. If you're changing, let the tank run fairly low, break up any crust, and then fill with the new salt. For mixing questions, see can you mix water softener salts?.
So which bag goes in your cart?
- Cabinet softener, city water, no issues: Diamond Crystal Bright & Soft, or Morton Clean and Protect if you want the additive.
- Two-tank softener, hard but clean well water: either brand's crystals, whichever is cheaper.
- Orange stains in the brine tank or on fixtures: Iron Fighter (any form) or Rust Defense pellets, and test your iron level.
- Trying to cut sodium: K-Life or Morton potassium, and turn up the salt dose.