Converting from HOB to Sponge Filter

[Lds760]

I have a 20 gallon long - cycled / well-seasoned tank with a HOB filter. I want to convert to a sponge filter to start a Cherry Shrimp tank.

I plan to run both the HOB and the sponge filter in parallel for a while to get the sponge well populated with bacteria before removing the HOB (and before putting the Cherry Shrimp in).

How long would this take?  The answer is probably “it depends” but are we talking a few days or a few weeks?

 

Any advice?

[Nuggets Beard]

I've replaced a canister filter with a Co-op sponge filter.  I let both go for a month.  Removed the canister.  And nothing happened.  All parameters remained the same.  I think at least a month, a little longer to make sure.

[xXInkedPhoenixX]

I think a month is a comfortable amount of time as  @Nuggets Beard said. 

[Gigrantor]

I’d say a minimum of a couple weeks. Remember that there is also beneficial bacteria in the tanks environment to help out (Substrate, glass, ect). Between the two, it should give the sponge enough of a jump start.

[DaveO]

You can jump start your sponge filter quickly if you want to. Just get a bucket of your tank water and clean out the hob filter in it. Now get the sponge filter running, air stone and all, and run it in the bucket of bacteria laden water.  Of course you need to reinstall the hob filter on the tank. After one or two days the sponge filter is good to go in the tank. Remove the hob filter after another week or so.

Edited December 20, 2021 by DaveO

[StevesFishTanks]

On 12/19/2021 at 9:27 PM, DaveO said:

You can jump start your sponge filter quickly if you want to. Just get a bucket of your tank water and clean out the hob filter in it. Now get the sponge filter running, air stone and all, and run it in the bucket of bacteria laden water.  Of course you need to reinstall the hob filter on the tank. After one or two days the sponge filter is good to go in the tank. Remove the hob filter after another week or so.

Thats a great idea. 

I would use that method if you plan to not use the HOB anymore after switching.

Personally I would keep both filters with a prefilter on the HOB

[KaitieG]

I'd also probably just keep the HOB and stick a pre-filter on it if you don't have one already.  I have shrimp doing great in a tank running a HOB with prefilter sponge.

[RonBFree]

In new tank I install the sponge filter and squeeze out a couple dirty sponge filters into the water.  

 

[CalmedByFish]

Just a heads-up. Shrimplets (and fish fry) easily fit into the holes in a coarse sponge filter. For my shrimp, I removed the coarse sponge, and used rubber bands to wrap the intake in filter floss. (A sponge with tiny holes would've been better, but $, ya know.)