Im having hard time cloning help

i have a problem cloning .i tried it twice now and its not going well,i have 6 plants 40 das old about 50cm keep em under 430 hps son agro .first time i cut clones about 2weeks ago and half of them died in the first 4 days some are still here but they dont have any roots and the new ones i made 3 days ago eather have their stems brown and sort of burnt or roting i dont know whats wrong.i cut em under water on some i used rooting hormon powder some i just left clean and i plced 5 in cups whit water the rest i placed in
oasis cubes as i saw on this forum.i keep 2 flouresents 18w ,36 in total at a distance of abot 40 cm temp.24-25c in a closed dome whit a little crack for fresh air.can someone direct me .what im doing wrong

Well first thing I see is the dome with a crack in it. You want to make is so that the moisture stays in. If you have a crack in it the moisture escapes.

I have cut many clones and have yet have one dye on me. This is what I do and use
For Rooting I use Green Light Rooting Hormone. I cut my clone at a 45 degree angle, wet it and dip it in the rooting hormone. I have a Jiffy-7 peet pellet ready to go. I place the clone into the pellet about half way down the pellet. Push the hole closed and then put in the dome I have. I use CFL's for the lighting and have it on 24/7 until I see roots sticking out of the peat pellet. I then plant pellet and all in the pot I want my plant in. I plant it deep enough to cover the pellet and just a little of the clone.

During this time I never - never open the dome. I use have a small cabinet that I use for cloning only and I have 6 26watt (CFL) ( 100watt equivlant) in this cabinet about 6 inches from the top of the dome. I hope this helps you

right now i make a areo cloner i saw on this site i wana see how that works,the last time i used oasis cubes i failed 3 times in aero 50 clones in total i dont know what is the problem i hope this aero cloner works.does enybody know how high do the tips of the cut clones need to be from the bubbling water when i place them in the cloner

and is it necesary to change the water in the aero cloner every day or can i change it every week

It may be the oasis cubes. Try to use rockwool. I have 100% success with it. I soak it in Grozime for a while, drain it good. Keeping it moist but not dripping. Lightly mist the clones clones daily, I also fan them a bit too when the dome is off. I also wipe any access moisture from inside the dome daily before putting back one after misting the clones. I do keep the dome vent open a crack. And my temps stays constant at 24c/75f. Under a flouro grow/aquarium shop light. I use liquid stim root on the cut clones before putting them in the rockwool and will have rooted clones witin 2 weeks.