green algae in iron reservoir

[itallwentwrongat30]

Hi guys! Hoping someone can help. So my (Swan if that makes a difference) iron stopped - well ironing. It was still hot but not doing much and the steam function just wasn't workin. I opened the water tank bit (it has the separate steam generator) and it has some green algae like material in it - eek!!!! How can I clean it? I have no vinegar in the house and given the lockdown situation realistically i don't want to go out specially - and I won't be due another food shop for about a week. can I use bleach or will that transfer onto clothes afterwards? Am I best just to use an old toothbrush or something and scrub??

HELP!!! TIA

Is it a clear plastic? If so stick it out in the sunlight or on a sunny windowsill.
Our iron says to empty the water out after each use but we always forget so end up with green in the tank and a day or two in the conservatory in the sunlight & a rinse out gets rid of it.

It is clear/lilac if that makes sense. I always forget too - and it hasn't been done in a while. Thanks for the tip!