Interesting. I don't have an aspect between my Merc and Saturn unfortunately, but it's true that Water and Earth are the two elements I feel least comfortable with. Either the energy they represent is totally nonexistent or, when I try to engage them, I easily go overboard--I can get obsessed to the point of anxiety with making sure everything's in order and that I'm working towards my goals (earth)--or I'm completely lazy and irresponsible. I can spend hours and hours daydreaming (water Merc, I think)--or I'm only focused on what's right in front of me. It $ucks because Earth and Water are supposed to be compatible elements but it doesn't seem like they are at all. Saturn/Cap's goal-oriented energy feels very antithetical to Piscean wandering. If anything, I think I'd be better off with a Fire/Water singleton mixture or Earth/Air.
Mercury is an inferior/dependent planet, which means it's easily colored by the superior planets. The superior planets are Mars, Jupiter, and Saturn which means they all have the power to drastically modify the inferior planets and aspects would give it the most personal and direct way of modification.
Since you do not have an aspect between your Mercury and Saturn singletons, it will be harder for Mercury to receive any assistance from Saturn, esp. since Mercury is in a debilitated state and Saturn is domiciled. Saturn recognizes it can assist Mercury but being that there's no direct relationship (aspect), there isn't much communication, but only recognition.
There is symbiosis between the elements of Earth and Water because Earth helps Water by giving structure/direction to flow, while Water gives Earth the needed resources to be functional. There is recognition between the signs of those elements that they can work together, even if there's no aspect... but it will require a lot of effort on your part to make those planets work in your favor, otherwise, the singletons are on their own without any sort of assistance/support.
I suppose, you'll have to really crack the whip on your Mercury to "create" a bridge to Saturn, if you want to reap more of the rewards of getting Earth to give purpose to Water.
Since your Saturn is a singleton, I suspect that you'd learn to get "comfortable" with Earth Saturn's energy during your return in about 4 years. People don't really get comfortable with Saturn (as a general thing) until they are "forced" to, not even those with dignified, angular Saturns (like you and I).
May28, I think you mentioned in another thread that you handle your singletons by doing something productive (Earth) with your emotions (Water)? Is that right? If so, that's a good idea, and I'll have to give it a shot! All the more reason to try and get into filmmaking, I suppose.
Yes, I mentioned that in my first post on this thread.
Our case is interesting in the sense we kinda have things in reverse. We both have Earth and Water singletons with one in a superior planet and one in an inferior planet. However, your superior singleton planet is domiciled, whereas my superior planet is corrupted. Your inferior planet is corrupted, whereas my inferior planet is a friend to both domiciled and exalted versions of it. Your singletons don't aspect so you'd have to put some effort in forging ties between them, whereas my singletons have an exact aspect which means, for better or worse LOL, they are tied together.
I have Earth Mars and Water Moon. In general, Earth in Mars is the most productive element for Mars as that cools Mars' naturally choleric state and adds practicality, whereas Water for Moon is the correct element for the Moon but it requires a LOT of discipline to control emotions. The signs recognize that they can work together to accomplish something, and as an added level of assistance, Mars and Moon sextile exactly, which gives me a better sense of conscious control. My temper is controlled, via productivity, and my Moon is very expressive when it comes to any sort of action. The thing I cannot really control is that Pisces Moon is extremely hard to contain. Then there's the issue with my superior planet who's supposed to be in charge of the whole operation and it's corrupted, so there will be times when there's stuff that explodes more than expected/normal. The combo shows that there are times when my emotional expressions can appear like I'm crazy and I'm exploding, when in reality, my normally placid Mars has it all under practical control.