Little background. Tiled my back splash in the kitchen went just fine. Level of experience previous was zero. I watched a couple tutorials and read up a bit. Went very smooth with 1"x1" mosaic tiles and sanded grout. No cracks or abnormalities. Decided to tackle the tile in the bathrooom. Gutted it complete redid everything from walls to plumbing. Installed tile and grout and all was good until about 3 months later then there were hair line cracks developing everywhere. Spend the last 5 months slowly tearing the grout lines out a couple feet at a time bc i have a daughter i am watching while my wife is in nursing school so i cant dedicate a lot of time to grind that stuff out. Finally get it all cleaned up and removed. My theory was i rushed putting in the grout and didnt let the tiles setup enough and harden or bad mix of grout bc i didnt use a power tool did it by hand. This time used one complete 25# bag of sanded grout appropriate for the size of the grout lines. measured the water exactly. used a mixer attached to a drill and followed a stopwatch for time. used a new bucket never used before. Put the grout up quickly, and got it wiped off well. A couple days later still looks wet in certain spots. Figured maybe it was related to grout haze in the lines so i used grout haze remover over the walls tonight and it did nothing. Still there, and I put a hair dryer up on the line to see if that would help it go away. It didnt, after some research it seems it could be bad mix? contaminated the grout when mixing? wiped off the dye when wiping the tiles off after application? Whatever happened i dont think i will redo it. Just live with it if it just an appearance thing. If i seal over it like this will it ever work its way out or wil it seal in the color? Last thing, i heard someone say they didnt use cement grout anymore they used epoxy grout? Is this basically taking sanded grout caulk and running that in the lines? If so could i do this the next time i did a project bc i am getting tired of having these grout lines get messed up. Total cost to fix it was just $25 for harbor freight reciprocating tool to remove grout and maybe $40 dollars worth of disks, and another bag of grout. So not like its cost me much monetarily speaking i just wasted a few months messing with it. Is there an easier way to remove the grout lines other than that tool bc that took forever, like 10 minutes for a one foot section. Here is a pic of the grout lines, basically the whole thing looks like this kinda splotchy. Edited the pic in lightroom to bring out the defet to see better. But trust me its fairly pronounced against the dry grout. When wet you cant see it.