New canister filter and ich

After the Great Covid Flood of 2022, I only had my hang-on filters to go on my new tank, which were barely adequate. However I was keeping up and I have now managed to buy a canister filter to replace them, which I'm very excited about.

The thing is, yesterday I discovered ich so now I'm treating the whole tank. Should I wait until the outbreak has cleared before installing the new filter? Or is now the perfect time to install it? Carbon-free of course.

(The ich outbreak occurred I'm certain because I had to do a 50%+ water change and it's a big tank. I think I did it too fast and so the temperature dropped pretty rapidly. I know, rookie error. Will a new filter stress them out? The ich is only showing on some of the tetras and the molly. The platies, minnows, angels, gouramis cories, plecos and loaches have no signs
... yet)

 

Can you add the canister and leave the hang-on filters running? That would be ideal since the cycle wouldn't be disrupted. You can then remove the hang-on's one at a time at later dates.

 

Can you add the canister and leave the hang-on filters running? That would be ideal since the cycle wouldn't be disrupted. You can then remove the hang-on's one at a time at later dates.

Well that was how I'd planned to do it originally but then I wondered if it would be good to run ichy water through brand new media.

And I had to remove the cartridges from the hang-ons anyway as I didn't want to rip them open to get the carbon out. So they only have new foam plus the existing foam in them now.

 

It's ok Ich won't contaminate media. Make sure there's no carbon in the new media if you're medicating.

 

I have a canister filter on one of my tanks, but I also run a HOB filter in that tank. I also suggest using prefilter sponges on the intakes of your filters. When you start to see the flow rate start to drop, rinse out the prefilter sponge. Normally, I can run my canister filter for many months without cleaning as long as the prefilter sponge is in place.

Every time you clean a filter, you are removing a portion of the beneficial bacteria. When you have two filters in service, only clean one of them, leaving the other alone for that maintenance session. That keeps the biofilter stable. I am not saying that you will have issues with running only a single canister filter, but there will be less risk with two filters.

Many HOB filters have a replaceable cartridge. If you have one of those filters, every time you toss out a cartridge, you are tossing out a lot of your bacteria with it. If you do have that type of filter, it is better to replace the cartridge with a filter sponge or a filter pad that can be rinsed out so you do not toss a significant portion of your biofilter.

 

Thank you!

That was actually what I had been planning to do.

I don't use cartridges in my HOB filters - they have Purigen in bags and carbon foam. I was going to put the Purigen in the canister and use Matrix with the carbon foam in the HOB. Mainly because I have Matrix already and I can't afford to buy more Purigen just yet!

(I removed the carbon before treating for ich.)

 

If your tank is planted, you do not need carbon and might not need Purigen. Activated carbon removes both things you need and things you do not need. In a planted tank, it can do more harm than good. In a tank with no plants or only artificial plants, use of carbon is OK.

Purigen is designed to remove organic compounds. If you are not overfeeding your fish, you probably do not need Purigen. A well functioning nitrogen cycle will break down uneaten food and fish wastes and convert it into nitrates which are then controlled through routine water changes.

If you have both a canister filter and an HOB, put coarse, medium, and fine filter sponges first, then ceramic rings and finally your Matrix in your canister. Use either foam sponges or filter pads in your HOB. If you need Purigen, you can add it to your HOB when needed and remove it when it is not needed. The problem with Purigen in a canister is that it would take a lot of it and you cannot tell whether it needs regenerating unless you open up the filter. You would have to have two large batches of Purigen, one for use in the canister and one for regeneration purposes. If the Purigen is in the HOB, you can just remove the bag when it needs regeneration and put it back after regeneration without having to dismantle the filter. If you are using Purigen, you should not need the carbon foam, just use plain polyurethane foam sponges or polyester filter pads in the HOB.