Ascaso In Tank Rechargeable Water Softener/Particle Filter for Espresso Machines - 24 L (D107) Review (2026)

What this filter does

The Ascaso D107 is an in-tank water softener and particle filter built for espresso machines that draw water through a tube sitting inside the reservoir, rather than machines plumbed directly into a water line. It sits in the tank and pulls water through a bed of ion exchange resin as the pump draws from the reservoir. The resin softens the water by exchanging hardness minerals for sodium ions, which reduces the scale that would otherwise build up inside the boiler and brew group over time. Because the filter also acts as a particle screen, it catches loose coffee grounds or sediment that might otherwise end up in the pump or valves. It is sold as a genuine Ascaso part, so it is sized to sit correctly in Ascaso tanks and in the many similar machines that share that tank style, including several Isomac, Quickmill and Expobar models.

Rechargeable resin instead of disposable cartridges

The main selling point is that the resin bed is not a one-time disposable cartridge. Instead of throwing the filter away once it is exhausted, you recharge it by soaking it in a strong salt water solution, which restores its softening capacity. Manufacturer guidance for this style of Ascaso filter is to recharge roughly once or twice a month with salt, or after roughly every 24 liters of water has passed through it, whichever comes first for your usage. For a household running one or two drinks a day this is a manageable weekly or twice monthly chore. For a small office or busy home bar pulling many shots daily, the 24 L threshold arrives quickly, which means recharging becomes a more frequent task than with a larger cartridge filter.

Fit and installation

Because this is an in-tank unit rather than an inline cartridge, installation is simply dropping it into the water reservoir where it sits over the intake tube. There is no plumbing, no extra housing to mount, and no tubing to cut, which keeps setup quick compared with countertop softener systems that sit outside the machine. The tradeoff of this simplicity is that it only works with machines that draw from an internal tank; it cannot be used on models with a direct plumbed-in water line or on machines where water is drawn from the very bottom of the reservoir rather than through a raised intake tube, so it is worth checking your machine's water intake style before buying.

Maintenance and the salt recharge step

Recharging with salt water is an extra maintenance step compared with cartridge filters you simply swap and discard. You need to prepare a salt brine, soak the unit for the recommended period, and rinse it before returning it to the tank, and skipping this step regularly will let the resin exhaust and stop softening the water as effectively. Some owners have also reported a bit of water flow resistance when the filter is brand new, which typically eases with use. None of this is difficult, but it does mean the D107 rewards owners who are willing to keep a basic recharge schedule rather than ignoring filter maintenance until scale symptoms show up.

Who should buy it

This filter suits owners of Ascaso machines and similar tank-fed espresso machines in moderately hard water areas who would rather recharge a resin bed than keep buying replacement cartridges. The particle filtering is a useful bonus for anyone worried about grit reaching the pump. It is a weaker fit for very high volume use, since the 24 L capacity means frequent recharging, and it is not an option at all for plumbed-in machines. Anyone unsure whether their machine's tank design is compatible should confirm the intake style before ordering, since fit is specific to tank-fed designs.

Frequently asked questions