I use the larger 2-inch jiffy pellets and never see roots on my clones until Day 7 in the dome.
Biggest factor is to make sure you have as much humidity as possible within the dome. Invest $25 and get a seedling mat.
The mat is slightly larger than the most common domes and raises the temperature just a few degrees. But that is enough
to keep the humidity up where you need it. IMPORTANT - you should see condensation on the inside of your dome EVERY TIME
you check it. The condensation is proof you have 100% humidity in the dome. Along with the mat I keep 1/2 inch of water in the dome.
Enough to completely cover the floor of the dome. The water, along with the mat, enables the humidity to get high and stay that way.
I have to add a cup of water or so to the dome every 3 or 4 days.
You will hear pro vs. con on wether or not to mist your clones inside the dome. I'm for it. I open each dome 4-6 times a day to mist the leaves
and allow fresh air into the dome. Cuttings/clones have no roots to absorb water so must rely on the high humidity for hydration. I figure I'm
helping by misting.
Most domes I've seen have some kind of slide that you can open to let some air into the dome. I keep both vents closed for the first 3 or 4 days
the clone is in the dome. After that I slide the vent open for the rest of their stay.
Ventilation - not a factor.
Light(s) - Rooting clones don't like strong direct light. I have mine under a 60W bulb that is on 24/7. If it is easier to place a piece of light cloth
over the dome instead of moving to another room, that'll work too.
Nutes - not a factor. Use regular water in the dome.
Waiting - I specialize in indicas and find that just about all my strains will show roots by Day 10 or 11 in the dome. But I'm using the bigger pellets
so I can take larger clones, means I would see roots 1-2 days earlier with the regular size pellets. Anyway, if I don't see roots by Day 12 or so I toss
the sucker out. I know from experience how long it should take to root a healthy cutting. So if a clone is that slow I don't want it anyway. Slow in the dome
means slow veg and flower too.
Some kushes take an extra day or 2 to root. Sativas take longer all the way around.
OPTIONAL - I've developed a neat procedure for domed clones. My bigger pellets sit firmly in a 9 oz. clear plastic solo cup. I drill drain holes in one cup,
put the pellet in that cup, and set that into another solo cup with no holes. This way I can set the cups in the dome and not have to worry about the water
siphoning from the dome floor to the pellet. Every 3 or 4 days I pick the clone up and remove the top cup. Then I set the holed cup into a bit of water for 3-5 seconds. This
lets me monitor how much water the pellets recieve. Too soggy and cuttings won't root. Too dry and cuttings won't root.
Good luck. PM me if you have any specific observations, commects or complaints. Always glad to help.
BigSteve.