[Graybeard58]

My front loader takes liquid detergent only. Does TSP come in a liquid form? If not, I suppose I could just put the powder directly on the clothes at the start.

[OldMissileer]

I would try to dissolve it into the liquid detergent. I would not want to put it directly on the cloths as a powder because it will not mix properly in the water.

Check out post #52, there is a link to a seller of STPP, Sodium Tripolyphosphate. Shipping costs some but it is the stuff they actually put in the detergent and may not hurt the fabric so much. I must say that I have been using TSP for awhile and I have to wear black pants and the TSP has made all my darks look better and has NOT affected the fabrics.