What ratios are appropriate for water to mix when making up some modified thinset? I'm using RS "Level Quik" if that helps.

Thanks to the folks on this very board, I'm not flipping out over a fairly long crack I found in the floor of my slab-on-grade house in San Antonio. Our pediatrics office told us that our carpet was contributing heavily to our oldest child's allergies. After pulling up the carpet, we have no way to disagree. Disgusting. We're planning to stain and seal the concrete and leave it a bare floor. A lot of businesses do it around here and it looks great.

That said, I have this long set of cracks running from one side of the house to the other. The cracks are tight on the edges of the foundation - ZERO gap - but they spread out to about 0.5mm (sorry... military guy by background and I don't estimate in inches well) at the very widest. The crack has a segment in the middle where there is no visible cracking... yet. The house is about 12 years old.

Some time ago, I asked about fixing this sort of thing and was told that a modified thinset was what was needed. So... I went out and purchased a bag. The only issue is that I have no idea what parts water to mix I need... and I don't know what it is supposed to look like once I mix it.

Anyone have any suggestions?

There are many tile experts here at AMHD. Look upo blkjack and try to send him a private message asking to read your post.

For tiling I mix to consistency about like soft ice cream. Stick your finger in it. When you pull your finger out it should leave a small peak. You would want a consistency stiff enough to trowel and soft enough to flow into or be pushed down into the crack.
Is Level Quik a tile setting compound or is it a floor leveling mixture? Sounds like a floor leveling mixture.

Thanks, guys. I'll try the soft ice cream approach. Glad I asked, since I had intended to mix it to the consistency of maple syrup. I assumed it had to be very thin in order "seek its own level" as claimed on the bag.

Maple syrup or pan cake batter mix is not bad. Especially since I think what you have is floor leveling material.