clones wont root

i have been doing clones for about 7 years now and never had a problem but now they just start the root nubs and then stop. i am using rockwool with a touch of jump start soaked cubs over night to lower ph to 5.5. i have a dome on them as i alway did until the roots start. i have them under a 26 watt cfl daylight bulb. the root zone temp is about 80 degrees. the mothers are healthy. the water is city but i run it throw a charcoal filter which i change every 2 months.
help i am pulling my hair out!!!!!!! what hair i have lol

i use rockwool too and sometimes the holes are to big and the stem dont make contact, even when u squish the top into the stem 75% of the stem still isnt touching .i make a new hole in the cube beside the pre made one and use a pc of stem i cut off a mom to make the holes just alittle smaller ,, try a cfl thats a bit more blue ,, it could be the strain too,, mites or trips ?

Is the mum getting old and scruffy? Are you sterilizing the cloning equipment?

I have been doing clones in RW for a long time as well. Every now and then I have a shitty batch. Nothing changed and I can't explain why, so I just clean all of my equipment and the next run of cuttings will usually be fine.

no the moms are lush i do sterilize everything every cloning
just got back from the hydro store and the guy said i might have better luck with oasis cubes
he switch from rockwool and found he had better results

are u using powder or jell ? power some times will leave a big not at the end of stem right b4 it starts too blast out roots..i have found that if i have to much powder on this happens ....i know longer use rw i use some brown like sponge i cant even think of the name but i get 50 damp in a sealed bag and now ill never use anything else and my % has always been 95% success on clones but some times rw would throw me a ringer ..and also some plants are a bitch to clone til u figure out just what they want ,thats not often but it happens

they are the oasis cubes i mentioned. one thing i noticed as i just cloned another 25 that when you push them in the cube you can feel the stem solidly held by the cube the ph is between 5.5 - 6.

i herd oasis cubes r funky. if youve done this for 7 years an u didnt change ne thing its probly the mom. but thats my 2 cents, have a growtastic day.

A sure fire way to get them to root; get some 12 ounce cups. Grab some seeding soil mixed with potting soil. Once the soil is in the cups get it wet and let them drain out. Dab a little gob of the cloning gel in the center of the cup in the soil where you're going to place the clone. From there do everything the same you would to clone, but put the clone right into the gob of cloning gel in the soil. From there just put a bit of dirt around the base on top of everything to hold the clone in place and in the gob of cloning gel. Since using this technique I use a bit more cloning gel, but I've been 99.9% on getting clones to root and survive.