Possible Bacteria Bloom

[AxieTails]

Hello all,

I did a water change last night and am worried there might be a bacteria bloom going on in Neo's tank. I've never dealt with this before so I was hoping to get some second opinions.

Tank setup: I've had this tank for years. It's a 20 gallon with sand and artificial decorations. I use a Tetra Whisper Filter with bio bag filter cartridges. I treat the water with Seachem prime and add a mineral solution similar to Holtfreter's. I usually do a 9 gallon water change ever 2 weeks. For about a month I've also been using an aquarium chiller, a cheap one by Poafamx. It has a small pump I kept submerged near the top of the water level. I had it set to keep her between 65-68 degrees Fahrenheit (18-20C)

Last night I noticed an off white slimy film inside of the chiller tubes and the filter. I'm embarrassed to say the bio bag looked quite filthy, it was very brown and slimy.
I continued with the 9 gallon water change, scrubbed the filter with primed water, removed the chiller, and have been keeping Neo tubbed out of caution (She has a towel covering one side, a small fake plant and I change the water 100% around every 12 hours). The filter has been running with a fresh bag for a little over 12 hours and the water still looks a bit blurry. I've also noticed white chunks, which I'm assuming are bacterial debris since none of her food is white.

I just tested the water, coming out to this:
Ph - 8.0, Ammonia - 0 ppm, Nitrite - 0 ppm, Nitrate - 5.0

Is it possible that the bacterial overgrowth is just from the bacteria taking advantage of all the new surface area in the chiller?
I've looked at a few other threads and saw a people saying further water changes at this point can exacerbate bacterial blooms, so my plan was to keep her tubbed until the water seems to be staying clear. Before I add the chiller back in I plan on flushing it by running a mixture of primed water and vinegar, then with just primed water to rinse. Does this seem like a good course of action?

Thank you for reading this far. I'll attach some photos.

 

[wolfen]

the cloudy water is more than likely caused by bacteria bloom, you will need to monitor the tanks parameters due to replacing the biological filtration (Tetra Whisper Filters are designed more for aquariums with substrate due to the replaceable bio-media)
the bacteria will continue clouding the water until the bacteria is resettled into the filter.
the slime and gunk will be a combination of bacteria and muck which at times can build up in pipes etc.. it will sometimes come loose from the pipes resulting in pieces floating in the water.

 

[AxieTails]

the cloudy water is more than likely caused by bacteria bloom, you will need to monitor the tanks parameters due to replacing the biological filtration (Tetra Whisper Filters are designed more for aquariums with substrate due to the replaceable bio-media)
the bacteria will continue clouding the water until the bacteria is resettled into the filter.
the slime and gunk will be a combination of bacteria and muck which at times can build up in pipes etc.. it will sometimes come loose from the pipes resulting in pieces floating in the water.

Thank you for the response, I appreciate it. So since I have sand substrate using a Whisper filter should be okay?

The water seems to be staying relatively clear and not worsening, I've spot cleaned the chunks, and I've been checking the bio bag. I've placed her back in for now.