Filter Cartridges will be the death of me

[JayLB]

I have been setting up a 20g with a Marina 20Slim hang on back filter. Its a fishless cycle. This filter takes 4 cartridges. And they need to be replaced every 2-3 weeks. And let me tell you when I change them, they are DISGUSTING. However, changing cartridges is likely impacting my ability to cycle properly....and I wish I could use some other media. Is there anyway to modify the filter to use different media? Or should I switch to some other type? OR should I just stick with this filter?

 

[Deleted member 149562]

No need to change til they are falling to bits. Rinse them in old aquarium water at water changes. They should last several weeks or months tween media changing

Alternatively you can buy something like Kamishi or Superfish pads that can be cut to size and that are significantly cheaper than the filter manufacturers own. They too can be rinsed out when water changing.

But absolutely no need to be changing the media so often as 2-3 weeks, as that does affect the good bacterial effect.

 

[Slaphppy7]

Agree with the above, and you are correct, changing out the media while trying to cycle = not good

 

[lnsaneM]

You can actually take the cartridges out entirely and only fill up the right side section with fine sponge, then fill up the rest of the section with other types of bio-media. I think this works more efficiently than what it actually comes out of the box.

 

[Fishmanic]

Fitting sponges would be better in the long run as you can just rinse the sponges in tank water and reuse till they disintegrate which can take years.
If you continue to use the cartridges and want to replace them when they become overly gunked up, just replace two at a time...the other two will still hold the BB so you wont disrupt your cycle. Then a couple weeks later, change the other two.

 

[GaryE]

Measure the spaces and wander to the hardware store. You can pick up dehumidifier sponges, where I live, that have wide enough pores for filtering. You have to cut them to fit, and alas, change them every ten years or so. You squeeze them out monthly and put them back in.

I haven't seen that brand of filter before, but I have never met an HOB I couldn't modify cheaply to make it an efficient bio-filter. The problem manufacturers had with old tech is we didn't need to constantly buy media, and so the constant revenue stream wasn't there for them. Shareholders want returns, so inefficient filtration media was invented. It isn't a tech improvement, but a commercial one.