JBL UniBloc for CPi40

JBL UniBloc for CPi40 is the replacement foam cartridge for the JBL CristalProfi i40 and TekAir filters. Foam does two jobs at once: it strains the solids out mechanically, and it carries the bacteria that do the biological work. JBL specifies a 25 ppi foam in a round cross-section with a T-profile.

Key Features

• For CristalProfi i40 and TekAir: JBL lists both, and the round cross-section with its T-profile is what makes it fit.
• 25 ppi foam: a pore density chosen to catch solids without choking the flow.
• Mechanical and biological in one: it strains the water and houses the filter bacteria at the same time.
• Water-neutral material: JBL specifies a synthetic that releases nothing into the tank.
• Long service life: foam is rinsed many times before it needs replacing.
• Keep a spare: a filter with no foam is not a filter.

Looking After Filter Foam

• Rinse it in tank water at each service, squeezing gently rather than wringing it out. Never under the tap: chlorine kills the bacteria you are trying to keep.
• Replace it when it stops springing back or starts falling apart, not on a calendar.
• When you do replace it, keep the old one in the filter alongside the new for a week or two if there is room, so the new foam gets seeded.
• Do not change the foam in the same week as any other media.
• Service on a schedule. A foam that has slowed the flow right down has already stopped filtering properly.

Good To Know

• Rinse media in tank water, never under the tap. Chlorine kills the bacteria living on it, and those bacteria are most of what a mature filter is worth.
• Change one stage at a time and leave a week or two between them. Replacing every bit of media in one go strips the filter of its bacteria and the tank can cycle all over again.
• Media only works if water goes through it rather than round it. Fit it so it fills its basket without being rammed in, and check flow afterwards.
• Service the filter on a schedule rather than waiting for the flow to drop. A filter that has slowed right down has already stopped doing part of its job.
• A new foam cartridge is bare. Treat the week after fitting one as you would a new filter, and test ammonia and nitrite.
• JBL's FilterStart or another bacterial starter will shorten that gap, but it is optional rather than required.
• Check which CristalProfi you have before ordering. The i40 cartridge is not the same as the one for the i60 upwards.