Ziss Filter Help?

[Frost]

I'm having an issue with a Ziss filter that I'm having trouble solving.

To paint the picture: I have two 29 gallon tanks, one above the other, and each has a Ziss filter running in it. The filters are run off of an Aquatop AP-100, this air pump sits on the ground. Both filters have a check valve and an air valve (not currently restricting flow) near the top of each tank.

Both filters flowed fine for over a month, but recently the filter in the top tank has slowed to the point of occasionally hiccuping out air while the one in the bottom tank still has a steady flow of air.

I have tried rinsing out the sponge, I have swapped which outlets on the air pump the filters are plugged into, I've tried a completely different air pump, I've tried a different check valve, and I have tried swapping the air lines between the two filters. None of that has fixed the low flow of the top filter. Is something plugged up on the inside? Is there anything else I can try before taking the whole filter apart and cleaning it?

I've attached photos of my airline and of the problem tank, in the tank photo you can note the lack of a steady stream of air exiting the filter. Both of my 29s have the exact same filter and airline placement.

Edited July 15, 2020 by Frost

[Cory]

I would recommend cleaning it. It sounds like something is built up where air is entering probably at the bottom diffusion ring.

[Frost]

6 minutes ago, Cory said:

I would recommend cleaning it. It sounds like something is built up where air is entering probably at the bottom diffusion ring.

Alright, guess I'll give that a shot. I'm too used to HOBs and other external filters where there's not much to pull out of the tank to clean, wanted to avoid it if I could.

Thanks Cory!

[Frost]

Update: taking it apart and cleaning it did the trick! It's running good as new, hopefully it stays that way for a while. I'm just glad I didn't have to throw money at the problem.

Thanks again!