Questions regarding my grow medium

Using a sterilized manure 40% sphagum peat moss 40% perlite 20%. While reading happened across peat moss and how acidic it is (new to me) however the water in using (purified tap) is alkaline based (6. water runoff is coming out 6.3- 6.5 should be fine right. Seedlings just seem to be stunted and wondering if this is the,possible cause even with runoff right where I want it

Personally, I don't think runoff is a very good measure of anything... In theory it sounds good, but from what I've read it's not exact science. Wish I could be more help. Hopefully they hit a growth spurt.

I agree with sunny in regard to run off, especially in soil.

Id be concerned with that much manure. You didn't mention what animal or cooking time. I suspect that may hold the answer.

Should have some dolomitic lime in there to regulate pH and supply calcium and magnesium. I use ProMix HP that has all that and lots of perlite with Myco too for good soil dynamics when mixed with manure etc. The micro-herd is important in soil growing and is why organic indoor growers mix their concoctions then allow them to "cook" so that the bacteria and fungi in the soil to break down organic matter into the salts that the plants actually eat. I skip all that and use soilless with hydro nutes to cut out the middleman.

Your manure percentage is too high as well and your pH should be around 6.5. To get a more accurate runoff you should water to saturation, sit overnight then add enough water to get some runoff and test that. The immediate runoff will be way off but after sitting for 12 hours or so it will reflect a more accurate picture of the pH in the root ball.

Good luck!

Apprechiate the advice gents when I did test saturated the night before then watered in the morning to test runoff seemed on point but soils are mixed and plants are in ill have to keep an eye on it and test my runoff they don't seem to be doing horrible but short of trying to take the baby's out of the seven gal and remix my soil think ill just have to live and learn and see how this run goes