Changing filter cartridge

[Mistilynn]

So 2 days ago I did a big tank clean/ rearranging. I got the algae off of the decor & added some new things & removed all the old gravel replacing it with brand new gravel. Washed the moss balls. So the inside of his tank is very clean, But the filter is full of so much algae! To the point the water is coming out of the side rather than where it is supposed to come out (Supposed to come out where yellow oval is, Coming out at red)
I need to change the filter, But I have some questions first. Everyone here talk alot about the nitrogen cycle. I dont want to take away all the bacteria that may have created a cycle or may be starting one, But everything in his tank is completely clean & brand new, Even a 50% water change was done. Ive had this filter cartridge in for about a month, maybe a little bit over a month. So How do I change it without disturbing anything? (I don’t have a water testing kit, & it will be a few days before I can get to the fish store to pick one up)

 

[King Fisher]

Maybe take the cartridge out and scrape the algae off with a knife to get some flow through it. Run it another month then clean it up good with dechlorinated water.

 

[Autumnsky]

Also since you changed the gravel and cleaned do much, you might be in for a mini cycle. Removing gravel and replacing will frequently reduce just enough BB from the rocks to cause a spike in water parameters. I would do additional couple water changes this week, every couple or 3 days. Since you don't have a test kit it is necessary to do pwc to be on the safe side.

Cleaning tank is recommended to NOT do a whole bunch of changes and also cleaning at the same time, to limit the loss of BB.

Can you reduce the flow? Is that bag laying on top of the filter.

Give it a couple weeks to normalize - easy on the feeding.

If you are able to add a new filter pad into the back of the aquarium under where the water is sucked up into the filter, it will start to grow some BB and you can get a head start.

You can swish the old filter pad around in treated water or water dipped out of the top of the tank, not the substrate water which is pretty mucky when you do a cleaning.

Changing the pads aren't recommended unless they are falling apart.