BLUE TONGUE SKINKS

This is a bit of a daft/embarassing question, but in for a penny in for a pound...
I got Ventress on Tuesday, have been changing water daily, misting, checking temps. and humidity etc. he has had one meal of green beans, basil, rocket and lean mince beef on Wednesday. (due to have another meal today as he's just over 3 months old)
But I'm having a real problem spot cleaning!! I am searching daily, but can't seem to find any waste.
My substrate is a combination of coco coir fiber, sphagnum moss and some reptile soil substrate provided by the pet shop. (the pet shop also put some spring tails within the soil as a little clean up crew)
Basically my query is, 1) with him being so tiny still is it just a case of trying to find a needle in a haystack? 2)are the springtails just really efficient and getting there before i do?
thanks for any input!

The poos will be there.

What I did with my young BTs was I had them mostly on absorbant paper towels for their first 12 months , then introduced Kritters Krumble mixed with natural gum tree leaf litter.
My observation is skinks will establish a latrine area where they habitually go to the toilet, and if you can work out where that is , spot cleaning becomes a breeze (especially if you are using paper toweling or sheets of news print as the substrate).

Is more problematic if you have then entire viv lined with coco-peat or something absorbant and fibrous and dark coloured .... nothing for it but to change out all the substrate once a week , I wouldn't let it go longer than that. You should be able to spot the white urates if you can't spot the dark coloured poos and be able to remove the soiled area of substrate with it.

Hi thanks for that kingofnobbys, sorry for the delay in my response, i will sift through the top layer shortly and do one final treasure hunt and if not I will change it weekly.