My poor tiny cacti have turned clear, one from each container, is there anything I can do to save them :( I'll try and describe it, they are miniature cacti in small round globes smaller than a pingpong ball, that's how they came, I added each seed packet in but only two grew in each container, now one from each has turned clear, and one of the not clear ones is starting to get a clear base, please help one ball are barrel cacti I think and the others are sun somethings, they look brown but that's just because they are completely clear, also yeah I know that one guy is like long and falling over, I just don't know what to do
No. It happens to cactus seedlings sometimes, and they cannot be saved. I see that you have used peat as growing medium, and peat is a source of pathogens that can kill seedlings. Is this some kind of sowing kit including globe, peat and seeds?
Peat is naturally lower in pathogens than almost any other soil components which will hold enough water to start seedlings. It has a long and well-proven history of being one of the very best ingredients for seed starting mixes. It does tend to hold more water though than mature cactus like. Looks like you are killing them with over watering. Your seed instructions should have told you that before they get that size to really make sure the peat is getting fully dry before you water. Clear ones are gone, but I think there is one, maybe two saveable there. The big one in the first pic may make it on its own if you just let it get fully dry before you water, and then don't give near as much water as that next time. The one in the second pic is dead at the base, but the top may be saveable if you razor cut above the rot, let the cutting callus over in the open air for a couple days, then repot. I would use pure perlite in a cup, with another cup for a humidity dome, and keep the water dryish so there is just barely any condensation on the clear dome. I would water only with a natural fungicide like chammomile tea. You can do a Google search for "rooting cactus", but they are so young the rules change from the usual desert-cactus rooting methods, so a better search might be "rooting tip cuttings". Also make sure to get the dead stuff out of there asap. "Bad apple spoils the whole bunch". :)
No, that is something you learn from experience. It depends too much on the growing conditions, cuttings are more likely to become infected in some environments than in others. Seedlings that small cannot be left to heal for too long anyway, because they are not as resistant to dry conditions as adult cacti, especially without roots and a (relatively) big cut surface. If I would try that they would probably dry up and die, I prefer to graft them onto something suitable, but that can be challenging if you have never done it before (+ you need another cactus).
It doesn't need a full scab over the cut. You just want it to dry down a little so it reduces the moisture and chances of fungus taking over before roots can develop. 24-48 hrs then into a humidity dome that is not wet like in your pictures. While it is developing a callus, I will often just lay the cutting on it's side above standard potting soil, again not wet.