I was reading on a link about my fx5 and it stated that there could be problems if Eheim substrat pro was used in the media trays. When I switched filters that was the bio material in my old filter. It only filled up 2/3 of the top basket(the other 2 baskets are filled with fluval bio max. Has anyone else had problems with the Eheim media in their fx5? I did put them on top of a blue mesh filter pad also in my old filter besause the balls did look like they could fall through the holes in the basket. I do plan in 6 more weeks to remove them and use more fluval biomax. Can I wait that long?

i think as long as the eheim bio doesnt fall through the badket on your fc5 youshould be ok until you do the switch over to bio max. just be sure that the media that is staying in the filter is capable of handling the bio load from your fish or you will get an ammonia spike if not a mini cycle. keep a close eye on your water parameters and you should be fine.

After 2 months don`t you think that 2 trays full of biomax(4 liters) should be able to handle switching out the 3rd tray. I won`t be cleaning out the foam pads around the trays at that time. Thanks.

after 2 months you should be fine for doing the switch.
i would still keep an eye on the water jsut to be safe but i wouldnt forsee and issues.

the only problems i know of with the fx5 are 2. the first one being with very old models(the first on the market) the miro chip that stops and resets the unit was faulty. this was replaced under warranty for many people. I had this happen to me but i had lost my receipt.lol. second problem and is still a current problem is very fine media can fall into the base and get sucked into the impeller, braking it or clogging it. a simple fix is to place all media in netting bags before you put them into the baskets. its not just Etheim media its ALL media so the fact they only mention Etheim makes me think sales ploy. I use both media fluval and Etheim and have no problems. I have not used net bags either, but i may do it next time I clean.

if this happens to anyone a replacement impeller cost is £30. and fairly easy to fix.

Ok after reading shannons post I took my filters (fx5's) apart and cleaned them. Thx shannon for giving me a job i didn't want to do This is why you DO NEED to put a polishing pad or fine net bag in the bottom basket if you are using etheim bio balls.

the inlet to the fx5 impeller is around 1.5 cm. a new etheim bio ball is around the same size. holes in the bottom of the baskets are around 5mm. but the bio balls get smaller while in use (rubbing together with water flow). I put my Etheim bio balls in about 3-4 months ago and some have got wedged in the 5mm basket holes. yes they have worn down to 6-7mm already. as said above a easy solution is to net your media in the bottom basket. a fine net/polishing pad/ladies stockings would do the trick. to be extra safe I would net all the media if you are using Etheim balls. fluval bio rings don't need to be netted unless old as it becomes brittle and brakes when very old.

THX shannon for writing that up.

Good points re the Plastic balls, obvious if you think about it but like me i'll bet not many do, i think i will be putting ALL my media in netting as i clean them in my various filters, would you think it would be overkill to put more that one polishing pad in an fx5 or in fluval 405's? ie one on each level,
or are you then looking at the outlet slowing,
apology for asking questions on your thread Shannon, hopefully it's same issue

more than one pad would be overkill and will slow the flow. they block up fairly easy so you need to maintain them more often. I think the polishing pads are a great addition and if you can maintain the filter with them in, it will help lower nitrates in the long run cos it will collect all the small crap. you will change the pad so remove the waste before it gets turned to nitrate.))

marcus wrote:


Cheers Marcus