MarineLandMicron Filter RC-S 12/1 CT, Model: AQ-78254

This micron filter works too well. I put one in my Penguin Pro 375 and problem is that this is the first thing the water hits when it comes into the filter. In fact, it goes into the inside of this, then flows to the outside and to the area behind the stock filter cartridges. So the blue filters won't be doing much as this traps everything and gets plugged up. So..., I switched back to the media basket in which I put more ceramic media.But..., then I got an idea, I setup a second Penguin Pro 375 as a polisher. Put the micron filter in it. Put the foam pre-filter on the uptake and put two refillable media cartridges in the filter with very fine polyester media and run this on the lowest flow setting. No bio-wheels. Basically a super polisher setup. This works great.Edit 5/8/20 (4 days later) - Yup, I was right. Works so well that it is completely plugged up after four days. Noticed the waterflow was almost nil. Pulled the micron filter out and it basically held water. Going to clean it per instructions and re-install.

I installed one of these on a Penguin Pro 375. For a few days everything was great. My water was crystal clear. Then one day I was watching TV and noticed that I didn't see any water coming of the filter spouts. I removed the filter and moved it to the sink to test it. Impeller was working and strong, but it was not pulling any water through the filter. I thought it was broken so scheduled a replacement of the Penguin.The water started getting cloudy and algae started forming on the glass. I now realize how important good filtration is.When the new filter arrived, I put all my old media, including the micron filter, into the new Penguin. Guess what? NO WATER FLOW! So, as I was playing with the flow control valve, it came lose from the intake, and water went everywhere! It IS pulling water, but where is it going? So I turned it off and took off the micron filter. Voila! It works!Long story short (too late), this is not to be used for a long period of time, OR you have to change them about once every three days. I love crystal clear water, so I'm going to see what happens if I use one for 3 days, change it and see if I can get more days. I wish there was a micron filter that could stay in place.

First and foremost…. Read the instructions and do as it says (Most of the one star reviews saying “it didn’t work after multiple days of use”)It specifically says USE FOR UP TO 24 HOURS.Fantastic and simple filter, fits very snug and might need a flat head to help over tube…water went from junk cloudy to better clarity than the tap water out of the sink. 10/10! Buy the correct one for your setup, use as directed, and enjoy non-swampy water in your tiny fish world.

the overflow tube will not fit .. the opening in the top of the micron filter (rite size C for the 375 Pro) is too small.Anyone else having this issue? I sent one back already thinking it was just a fluke. Ill try once more. If it doesnt work this time the filter will go back too.

Delivers the advertised polish to your water. Do note that these are to be used overnight or so, and after that you need to clean and dry them. Think these would be good for when company's expected or you want to take some nice photos/videos. Don't see the benefit in everyday use, too much hassle.