Hi...
I have and like both and for different reasons...
Tufa... never had any of mine float either, is great for growing algae because it has a very rough surface which is great becase the fish can't pick it clean....
TXHR... it like nothing else for AF Cichlids... the holes are like rental apartments.... a fish moves in ... gets to big and moves ut and somebody smaller moves in....
In my 125G I have a mixture and in my 110G is 100% TXHR. Still waiting for a good friend with an awesome camera to take some pics.... hopefully this week.
Here is what I am going to do in the near future on the 110G...
I have 1 piece of TXHR that is 28" x 20" (at it widest point which is in the middle and will need to be chopped down a little), x 4". I am going to remove most of the rock, (which is a lot!!), and I am putting in a well cleaned longer type milk crate, on it's side and open to the back of the tank, with short sections of 3", 4", 5" PVC pipes about 5" long. They will be arranged like the milk bottles would have been and scerued in place somehow...
Then I am going to place the large flat piece of TXHR on top of the crate and wil probably overhang it.... then I have been collecting other smaller very flat peices and will use them to cover up the Milk crate... and wil use some of the existing TXHR to finsh off where needed.....
The goal is to give more space for lager fish without adding weight...
Here is where tufa comes in... I'll be getting rid of the gravel during this time and will place 3-4" chunks of tufa on the bottom of tank instead.... with no pleco and some new lights I am going for a totally green overhanging reef look....
Sometime this summer...
mm
PS/ the tufa is also a great base for putting larger more fragile peices of TXHR on!!!!