Hey everybody! So... I've recently gotten back to the idea of laundry soap making as I read some of the experienced soapmakers on here do it. I actually got into soap making because I wanted to make laundry soap, but got scared by some horror stories online and decided to stick with making body soap. I've used 'eco friendly' laundry detergent for a few years, but I feel it doesn't clean properly and I had to throw out a bunch of shirts because they smelled sweaty (even though I didn't overly sweat in them, it just didn't wash out and accumulated over time). I went back to regular high power detergent, but would like to have a more biodegradable alternative that washes properly and I'm hoping laundry soap can do just that. The problem is the water here is quite hard and I'm afraid of ruining the washing machine. We're renting, so I'm also not going to invest in a water-softening system.. With my body soap I barely get any soap scum if I add 2% of citric acid, so I thought I could make a laundry soap with 4% citric acid to be on the safe side (plus extra lye to react with of course!) The recipe would be a 100% coconut oil soap with 95% NaOH and 5% KOH. I'd use a superfat of -1 or maybe even -3 with a high water soap, like a 25% lye solution so if the negative superfat doesn't get cancelled out by the lye impurity, the excess lye can move out and react with air to form sodium carbonate like in the lye heavy Castile soap thread (IIRC there was someone who suggested it was because of the extra water that the extra lye could migrate out of the soap to react with air) I'd shred the soap and mix it in equal parts with washing soda as per DeeAnna's website https://classicbells.com/soap/laundrySoap.asp My questions: 1. Does this seem like a reasonable recipe for laundry soap for a hard water environment? 2. How do I check the washing machine for soap scum build up? 3. How much citric acid would be too much? I think I read on DeeAnna's website that most people stay under 2% because at higher percentages it can form some crystals, but I don't really mind how my laundry soap looks, just how it functions. Is there a disadvantage of using more CA other than crystal forming? https://classicbells.com/soap/citricAcid.asp 4. I always use vinegar in stead of fabric softener. Would that still be a good idea when using laundry soap? A big thank you to all of you for reading. I know this topic has been coming back a few times and I might be a bit stubborn in wanting to try laundry soap in hard water but I'm just really not happy with my detergent at the moment and want to find something better.