Review on Premium RO6G BCP Pre-Filter Foam Sponge 🐠 Roll – Essential for Crystal Clear Aquarium Fish Tanks by Anton Nosrac

When they need cleaning you can see them start to take on an hour glass shape as they are sucked towards the pump inlet. Reducing the flow of water as they do. Cleaning is as easy as removing and rinsing/spinning, saving you the trouble of disassembling and cleaning a large pump so often. I've only used two packs so far but one was oddly cut off as it had way more padding at the bottom than needed so it's not as deep and a little harder to hold on to than the other. I use, but I'm not that bothered about swapping it out for a new one before it fails completely, just pointing out that there may be some differences between them. 8 of them will last a long time and go a long way. Also the fact that they have a bottom in the first place is a plus as otherwise nothing bigger than sponge pores would be keeping the main filter away. I had a mysterious burst of ammonia suppressing the nitrogen cycle that I couldn't pinpoint exactly, and it turned out that my primary filter sponge was full of dead pest slugs. After cleaning and adding to the filter inlet, this problem went away practically overnight. Now if only the killer slugs could eat them faster than the pleco shrimp pellets they seem to like better.