Argh! How annoying (although the buffalo one does look like when my mega puppy, 60kg+, recently discovered running and jumping on frozen puddles

).
My first reaction is that there are two problems:
# The layers you’ve poured were too thick and weren’t allowed long enough to dry (between layers).
# I believe the cloudy parts are bits that haven’t dried fully yet and/or may have reacted badly to the moisture in the PVA (or maybe the paint).
From a brief scan of railway forums it’s seems these are both common problems, certainly with WS realistic water.
What’s your humidity? I ask as I live in a stone cottage in the temperate rain forest known as South Wales and moisture can be a real problem.
What were the conditions you left the terrain in whilst drying? What temperature do you class as room temp? (I ask because peoples ideas on what this is varies - in my house it would be 18°C which is 2/3° less than what some see as the norm). What paint did you use before adding the water effects? Was it the same on all pieces? I can see tiny white patches in the sand/base material on all of them - is that unpainted white base coat or (as I’m guessing) PVA showing? If it’s PVA it wouldn’t still be white when dried.
From the WS faq here
https://woodlandscenics.woodlandscenics.com/show/category/Water (bold emphasis added by me).
# Realistic Water and PVA glue are not compatible. Using the two together could cause the Realistic Water to act adversely, causing cracking and/or fogging.
# Residual moisture in the adhesive could be absorbed by the Realistic Water and cause clouding.
# Cure times will start taking longer the more layers you add. 3/4 in will take
weeks to achieve with Realistic Water. Therefore, we recommend using Deep Pour Water instead because it would be a much quicker process to achieve the 3/4 in depth.
# If you are using Realistic Water and are not using Earth Colors Liquid Pigments, check with the manufacturer to make sure the paint you are using is 100% acrylic. Most craft paints, including premium brands, contain vinyl fillers. Vinyl in paint could have an adverse reaction with Realistic Water.
Many ex-realistic water users seem to now use Envirotex Lite (looks like a resin) instead.
I hope this helps,
Andrew
BeneathALeadMountain
(Edited many times as I research

)