Gloopy beer!

[clarets7]

I would suspect the fish tank heater if it is directly in the wort. Others on here have put the FV in a larger vessel filled with water and the FTH in that. I used a FTH for a couple of brews but just didn't like the idea, so converted an old chest freezer.

[Dene]

Is it a good idea to have a weak chlorine bath permanently made up for storing utensils/tubes in like I have seen in a most breweries?

I keep one while brewing and prepping yeast pitch, however, I use my sanitizing solution. I rinse under the tap and put in the solution as I go - use and reuse.

Before cleaning the shed, if it's not too late, try a different heat source as the previous post about the fish tank heater could be spot on. I assumed you were putting it in a separate water container - but that's unlikely to work now I think about it. So direct into the wort would be the only solution to heating and that could be holding something internally that is transferring in and out with each batch. It would take much and a cleaning solution might not be strong enough to kill something like that.

I suggest a heat pad, or belt at the very least.

[Jocky]

Yeah, I'd look at the heater, fermenter and any syphon you use to transfer from boiler to fermenter.

A squirt of starsan is not enough to clean items - everything needs to be both visibly clean and clear of residue. Even if something looks clean it may still be covered in residue. Clean everything in bleach solution/oxy/vwp/pbw straight after use.

[Eric]

Cleanliness is important at all stages made more so if your brewing equipment or space is shared with others.
The moment boiled wort has cooled a little it becomes target for many types of organism you don't want, so everything it contacts should be sanitised sufficiently to avoid contamination. I have not found that tap water (inclusive of chlorine content) or the air (perhaps with exclusion of flying insects) in my brewing space pose significant threat.

I do not use starsan as I fear my very alkaline tapwater might cause its acidity to be compromised in circumstances of just using a fine spray, so stick to a regime of bleach and rinsing with tapwater. I would use starsan if my water was not so alkaline but if you have problems it might be worth a try with bleach. Anything that goes into wort will either be sanitised this way or, in the case of stainless steel spoons and the like, they are sometimes heated over a gas flame and quenched in the beer.