Eheim6664 Prefilter

This is a pretty large addition to the intake tube on my SunSun 704b...not easy to hide. It's charcoal grey color doesn't match with my other filter plumbing and sticks right out against my black background and sides.... But boy does it do the job!I have been setting up a new African Cichlid tank and stirring up a lot of fine white sand in the process. Not wanting all that sand in my canister I took a chance on the Eheim pre-filter fitting my SunSun plumbing...it did perfectly after shortening the down tube. The filter is made in two sections that come apart by pressing the light grey button on the front of the filter case. It doesn't just pop right off, so a little care is necessary to gently wiggle it off. Inside is a coarse white sponge that seems to be very effective at catching the bigger stuff as well as the fine white sand. Interestedly, the top section seems to collect more gunk, while the bottom section seems to grab the sand particles.I can see where this filter would be very handy for the aquarist that had a very large livestock load. They could combine the sections of two pre-filters to have four sections. On the other hand, a person with a small tank could elect to only use the top section. Very good design. My only whimper...make it in solid black. (Edit: Actually, it is black but somehow turns light grey once in the water. IDK why.)Edit 2/22: I would give this product 10 stars if I could. My 60 gallon Brichardi tank now has a school of 30 or 35 (who can count?) fish of various ages and sizes. As the population grew, I added a Polar Aurora filter for two big canister filters on this tank and of course added the Eheim pre filter. The SunSun 704b crapped out on me last month so I replaced it with an Oase 350. It’s down tube is the smaller size but I was able to fashion a reducer with a small section of tube. I’m back now to buy a third Eheim pre filter for my 29 gallon planted tank which has a problem with plant debris clogging the intake.I have learned that your biological filter will thrive better if left alone and not disturbed for periods of six months or more. I scraped all the “bio rock” and went totally with Poret 30 ppi foam for biological filter media. This means that mechanical filtration has to occur prior to bio. With the Eheim coarse pre filter and then fine sponge in the Oase pre filter before the water goes to the bio stage. Works great.

The media could not be loaded. This pre-filter is awesome!! While rather large it does seem to conceal nicely into the corner of my 55 gallon tank. I run the 250 model of Eheims classic filter, and with the help of a 2 inch piece of tubing it fits snuggly onto the original intake tube (which I have also been considering replacing with the gray/clear intake that they have here on Amazon)Since I've never had one of these before, I wanted to show how easy it is to take apart (which is the video I included)The only downside is the size- which I wasnt at all expecting. Each section is about 2.5 inches tall, and I'm glad that one is removable otherwise it wouldn't have fit. Last night my tank was a little cloudy (I was moving around some plants and adjusting the air stone) but I put this on, went to sleep and woke up to a very clear and clean tank.Cleaning wise, I am able to turn off the filter, disconnect the cartridge section underwater, easily wash it off, pop it back on, and turn the filter back on without having any funny business. Despite being pretty coarse, the media picked up a lot of the fine particles that were making my water look a little cloudy.The main reason I bought this, however, wasn't because of my water quality, but rather my 6 baby Ember Tetras, the 7th of which was sucked up through the original end piece about 4 days ago. Sad to say I have had this on my aquarium list for a while and the accident could have been prevented.Yet another great German product at a great price, thank you Eheim!

Ordered this for the wife’s fish tank, which it’s Marineland filter has managed to suck up more than a few fish fry (and adults) into its innards. Didn’t help that one of our Pugs decided the end cap to the Marineland inlet was a nice toy, so knowing Eheim makes quality aquarium gear, figured this was worth a try. I used to have an Eheim inlet filter for an older Fluval unit, so I assumed it would be a plus to the tank. The only area of concern would be if it would fit the Marineland inlet, which it did with a minimum of effort pushing into the inlet line under water. So far, it has kept fish out of the filter and should help reduce the load into the filter, since it has its own filter media.It appears easily expandable in construction for filters with more flow to them. Only negative is that it is rather large, and tends to stand out visually.Recommended.

Works great at keeping my shrimp/loaches out of the canister filter. One kuhli loach would always find his way into the canister, not anymore!Only downside is it can clog & slow the flow going though the canister filter, when doing water changes be sure to remember & clean these prefilters.

This prefilter is somewhat large for my purposes; it dominates the back corner of my 20 gallon. It would be perfect if there were a smaller version of it. Besides just hogging real estate, it's another semi-conspicuous eyesore to distract from the plants and fish. (I have strategically placed a lot of plants around it to partially obscure it.)It seems to do a great job of slowing down the rate at which the filter tubing becomes caked in sludge. Additionally, the prefilter itself is surprisingly low-maintenance for me; not requiring weekly rinses like some other prefilters I have. I believe this prefilter is using a polyether foam which is just the right amount of porosity to catch large particles but not get clogged rapidly as result.Overall it's a positive improvement to my tank, as it cuts down on the frequency of maintenance. I just wished it was more attractive and not as large.