Got a Kinetico, Harvey's or other block-fed water softener? Our block salt is 99.9% pure PDV salt in 8kg packs (2 x 4kg blocks) that fit every standard block softener cabinet. Single packs, bulk multi-buys and full pallets — delivered fast across the UK.
Need help with your choice? Call 01902214281 between 8 a.m. and 4 p.m.
If you've got a Kinetico, Harvey's, TwinTec, Monarch, Minimax, BWT or other block-fed water softener, this is the page you need. Every product here is block salt in the standard UK format: 8kg packs containing 2 x 4kg blocks that slot directly into your softener cabinet. No mess, no measuring, no hauling 25kg bags into the kitchen — just two clean blocks, dropped into place.
Every batch is 99.9% pure PDV salt (Pure Dried Vacuum salt — the highest food-grade purity available), tested before it leaves us. No fillers, no anti-caking agents, no impurities that build up sludge in your softener tank.
Block-fed water softeners use 8kg packs (2 x 4kg blocks) in a standard rectangular shape. The following UK softener brands all use this standard block format:
Both Kinetico block salt and Harveys block salt branded packs are universally compatible — Harvey's blocks work in Kinetico softeners and vice versa. The branding is recommended by each manufacturer, but the physical block dimensions and chemistry are standardised across the industry.
Exception — curved block softeners: A small number of UK softeners use curved blocks rather than standard rectangular blocks. These include:
Standard block salt does not fit these curved-block softeners. If you've got one of these models, you'll need to order the specific curved block format from the manufacturer.
The short answer: whatever your softener was designed for. They're not interchangeable.
If you can't tell which you have, open the salt cabinet and look at what's currently in there. Rectangular blocks → block salt. Compressed tablets or loose granules → tablet salt or granular salt.
Block salt doesn't go off, doesn't take up much space stacked properly, and you'll use it predictably year after year. That makes it one of the best household supplies to bulk-buy. Three options:
Stack pallets in a garage or shed — they arrive shrink-wrapped and stay dry as long as the wrapping stays intact. If you're worried about storage space, a full pallet is typically smaller than a standard chest freezer in floor area.
In practice, very little. Both are 99.9% pure PDV salt in 8kg packs (2 x 4kg blocks), manufactured to the same UK standards, and both are universally compatible with all standard block-fed water softeners. The difference is branding — Kinetico block salt is the manufacturer-recommended salt for Kinetico softeners, Harveys block salt is recommended for Harvey water softeners. You can safely use either brand in any standard block-fed softener.
For a typical UK household: one block per person per month is a good rule of thumb. A single person uses about 1 block per month, a couple uses 1.5–2 blocks, a family of 4 uses 2–3 blocks. Very hard water areas (parts of Essex, Kent, Suffolk, Cambridgeshire) push usage up by 20–50%. One 8kg pack contains 2 blocks.
Yes — both brands of block salt fit and work in any standard block-fed softener including Kinetico, Harvey's, TwinTec, Monarch, Minimax, BWT and Crown. The branding is purely marketing — physical block dimensions and chemistry are standardised. The only exceptions are curved-block softeners (Harvey Arc, Minimax Innova, TwinTec Cobalt) which need their specific curved blocks.
No — if you've got a Harvey Arc, Minimax Innova or TwinTec Cobalt, our standard rectangular block salt doesn't fit. These softeners use proprietary curved blocks that only the manufacturer supplies. Check your softener's brand and model on the front of the unit before ordering. For all other UK block-fed softeners (the vast majority), our standard block salt is the right product.
Most UK households top up every 4–6 weeks. Don't wait for blocks to disappear completely — refill when the blocks are about a quarter to a third of their original size. This gives the resin time to regenerate fully between refills. Block-fed softeners are typically designed for 2 blocks at a time, so most users add a new pack (2 blocks) when the previous pack is mostly gone.
Yes — running out of salt won't damage your water softener. It just means the system can't soften water until you refill it. Within 1–2 weeks of running out, you'll start seeing limescale return (kettle marks, dull glassware, less soap lather). Add new blocks, wait for the system to regenerate (24–48 hours), and the soft water returns. No permanent damage.
Yes — all our block salt is 99.9% PDV (Pure Dried Vacuum) salt, the same purity grade used in food production. High purity matters for water softener health because cheaper low-purity salt leaves insoluble residue (sludge) in the salt tank over time, which can clog the system. Food-grade PDV salt dissolves cleanly and leaves no residue.
