Your problem is you didn't wet the walls first. Hardi is VERY thirsty, and will soak up a lot of water. It actually sucks the water right out of the thinset. You need to wet it down really well, and then wet it down some more. It takes a LOT of water. A lot of people end up putting a coat of primer on it first, to alleviate the problem. I would pull down the Kerdi and start over. You might be able to scrape the thinset off of the Kerdi and re-use it. Cleaning the thinset off of the Hardi should be relatively easy.

Hi Chris! I was just checking in to see how it's all going for you? Did you get your current house sold? Did you get a good price on the MH with the upgrades you wanted? And did you make a decision on the tile showers? I learn so much from this forum! Sometime in the next 2.5 years from now, I'll be remodelling my bathrooms. I have a full bath with a tub/shower combo that uses a shower curtain rather than a sliding glass door, and I have a half bath in the master, just a toilet and sink. In the full bath, I want to take out the tub/shower that is original to the house (1979), and put in a small (4.5') claw foot tub. I'm debating putting in a shower head. But after reading Cathy's comment about tile, I don't think I'll put tile in, even though I'll reinforce the floor under the tub. I was worried I wouldn't be able to find a claw foot tub small enough to fit into a MH bathtub space of only 4.5', but I was wrong, luckily! Even Home Depot sells tubs, claw foot included, in that smaller size. Anyway, if you get a chance, let me know how it's going for you!

Good to know. It is going to be hard to get enough on the cloth to get into the ridges on the tiles the OP is using, without putting too much on the cloth so that it won't drip down the sides of the tile. So be careful, Dianey. That is going to make a nice floor, but you are going to have to be careful to dab on the grout release and not get any onto the sides of the tile. Let us know how it works out. If the floor is not installed yet, maybe it will be easier to put the grout release onto the top surface when it is still loose. Or maybe not. I am envisioning it attached to a clip board or something, and holding it upside down and dabbing the solution on it while it is held upside down! Anyplace where the grout release runs down the side of the tile, your grout is not going to stick.

We need to tie in approx 1,100 sq ft to finish up our ground floor. Checked with original store, local outlets, FB Marketplace & Ebay also with the contractor who laid the tile we have. It was discontinued prob around 2 years ago. There MUST be some boxes laying around somewhere?! 🙏