Almost 3 weeks ago I placed 18 san pedro and peyote seeds in cactus soil. After about 1-2 weeks 5 of them had germinated. I believe the ones that grows are all san pedros because they are growing in length and do not look like tiny balls. I searched on the sueface after the other seeds but could not find them. So they dissolve after a while? Why so few germinated?

Possibly the seeds sunk into the growing media after you watered them?
Seedlings growing in length are not necessarily not Lophs. They could be receiving not enough light and etiolating.

Thats probably the case.. They get indirect sunlight as long as the sun is up so I do not believe they are lacking sunligt. I will search the soil
for seeds after I have replanted those that are growing. How big do they have to get before I can do that? They are this big right now:

I may not be the best person to reply, having only germinated cactus seeds a few times, but to me it looks as if you are watering a bit too heavily and this may have resulted in the seeds getting buried. The seeds shouldn’t dissolve, at least in my experience.

How are you watering your seeds and are you covering them to save loss of water and keep the humidity level up?

I have found that the best ways to water are by using a spray mister or by watering from the bottom and letting the water wick up through the growing medium.

I water them from the bottom, letting the soil suck upp the water. I keep the pots in a transparent plastic jar with a lid on to keep the humidity high. I take of the lid a few minutes a day.

I did find that some of my trich seeds became hard to see against the colour of the moist soil.

I found out of all the seeds that I sowed the Pachanoi took the longest, possibly 6-8 weeks until all had germinated that were going to. I got ~50% germination with Pachanoi, but ~80% and much faster germination - 2–4 weeks – with Bridgessii and Peruvianus. I haven’t tried germinating Lophs so I couldn’t say how long they take.

To me your soil does look very damp however, I would maybe have a go with watering with a spray mister as it looks waterlogged. Growing medium only needs to be moist.

Seems way wet o me. I just had a similar scene around these parts. The little round guys you were hoping for took just over a week to show up.

I ran some perilite through an old but clean coffee grinder...making perilite sand. Mixed this with (flour sifter) sifted cactus potting soil and some standard sized chunky perilite. Sterilized the whole mix in the oven and then sowed seeds on top when it was cool. Used flour sifter to add a thin layer on top and then misted with desilled water until the surface was wet. I sprayed a couple times a day ( as the mist was not soaking in too deep ) the tray was set on my porch in mostly shade, no direct light. Plastic wrap wretched over top stays prett fogged with condensation.

1 week to the day and I had 25% of the little guys show up.

yea definitely get some per-lite in there and no need to saturate it, when it starts growing you could easily drowned it.

it is a cactus.