Looking for a clean sound

Press the "better" button! 

Without hearing the mix, it's going to be hard to make good suggestions. But as a first thought, since it sounds a bit like you might be finding it hard to get the piano to not get lost in the mix, maybe "clean" isn't necessarily what you need - have you experimented with the Condition slider? Depending on genre, that may not be suitable, but it can add character to the piano sound, and lift it in the mix.

Lovely moments in this Justin. Listened maybe half a dozen times or more - grows on me - Reminds me of a lot of things.. The big change (1.50s), very satisfying.. I'd love to hear this after you've remixed, if you do. None of this below is about criticism but constructive advice (just based on early impressions about "What would I consider" myself if I was mixing the piece).

There's much to consider and each suggestion comes with no single best way to go, so a list of possible things to zoom in on might hopefully lead to some things to try.

1
There sounds to me like there's a little shimmery distortion on piano esp. when it's exposed in the mix (like a hot signal went to tape, but not a warm valve one, a little harsh like a mild mid-range almost sizzle - just guessing a compressor issue) - by itself not a bad thing to add some warm valve blush, but maybe it is a little too broken sounding:

maybe lower Pianoteq's output volume a little (makeup in DAW) to run it in a little less hot, in case that's the source

and/or

lower any compression or harmonic exciters (plugins like channel strips etc. which might overheat things)

and/or

check to be sure you're working with the highest possible quality of Pianoteq output - you might get best results by exporting a MIDI performance to audio at high settings, in case something in your DAW is down-sampling somehow. (If poss, work at 32bit or 24 - and 48kHz at least but mix-down to 44.1kHz is still OK. I am often happy at 48kHz unless I'm doing excessive editing. A nice mastering tool can be a game changer for all your mixes.

2
Similar EQ competing with guitar:

try dipping some mid piano EQ first, raise trebles a little too (bass feels nice as is to me) - then play up and down with those values - but maybe guitar could be thinned first.

and/or

EQ each track differently (there's no "best" way - but a lot of the time, it's counter-productive to have similarly full tracks with full EQ - some tailoring can open things up enormously) - sometimes you can really open up a track by applying quite separate emphases per track, with a final mastering EQ on the master buss to bring together the full picture.

and/or

since guitar can boom (thumbed notes particularly) look or listen for the frequency of that, and lower it a little so not to crowd the piano's frequencies (a nice EQ with tricky tools built in can lower a range over a certain velocity - it's a good trick to learn about) - often easier to make a better share of the sonic space by EQing instruments with smaller frequency ranges first, then piano if still needed (it's a total range instrument so large dip or peaks in EQ can cause holes or spikes on certain keys or octaves - sometimes it's a matter just of EQing the notes being played to taste of course though).

3
Reverb feels thick (esp. compared to guitar which shines quite well):

try a few things like raising reverb's 'tone' (or if doing EQ in a DAW, cut bass and trebles so it's a soft mid band) and even lowering overall reverb can help (bassy reverb can cause mud)

and/or

EQ the reverb separately to the piano

and/or

put reverb on a separate FX track (different ways to do the same thing), give it a wider stereo image than the piano to give a sense of space and trailing off.

4
Piano mixed left, guitar mixed right:

I like the idea of that (pleasing artistic effect) but with any instruments with different frequencies, it can be creatively interesting to position and make 'full'. Only suggestion about that would be to hopefully have this work better with some of the above, esp. EQ and reverb. Piano and strings in this production style almost demands a full stereo sense (that's an opinion of course).

You might like to try double-tracking (or widening) L&R for guitar while leaving strings and piano largely across the stage. That way, the guitar, being doubled (maybe 2 tracks of same performance given a doubling effect with some randomisation (not strictly chorus). Various ways include many available plugins free and paid, or two performances.

In the song "Celtic Sway", the piano and guitar share the whole L&R a little more comfortably (in terms of gluing nicely tonally, and suiting the music, their bass range centers and melds, whereas in "Tempest" these different bass elements being separated can cause a kind of 'confusion' to the stereo image - not to say I'd want to change that production value, but worth trying a few things and work back from there).

There may be other choices to separate the instruments with EQ and compression and changing the stereo dimensions of their respective reverbs only (like throwing piano reverb more left, guitar reverb more right) - a combo of these kinds of things could be worth exploring for a few days before something you like might come.

5
Falling into pre-production territory, perhaps an overall too loud mix:

on that subject, there are many things touching on it - from maybe backing off the overall velocity of notes on all instruments, giving more dynamic space and range.. it's not a simple science but you might profit from thinking of each instrument not needing to be loud at all times - just more dynamics including gentle notes (not necessarily whole gentle bars or verses)

In general, there's a world of really great and worthwhile plugins for mixing in a DAW and lots of useful info all over the 'net. We all find out what we like to do, how we like to sound over time and you can't go wrong spending time getting to grips with some nice mastering tools. You could get value from a console-like plugin with good EQ and compression and a fine reverb unit (or Pianoteq'a own).

In terms of recording, there's a difference to raw VST instruments (as good as they can be) and what a final mix can become. The mix is all about all the instruments and tones coming out of 2 speakers (different discussion than piano-in-a-room with different goals).

Sincerely, keep mixing and experimenting - really like your ideas. Cheers.

You're most welcome Justin - keep truckin'.

In case you enjoy a read and some thought experiments, thought I'd expand (not going out of my way - rather enjoying thinking about this in terms of the potential I hear in your recordings - a nice Saturday).

I neglected to mention about particular Pianoteq presets/pianos but I do rather like the piano you've chosen and the production lean you put on it already.

In a way, there's no best Pianoteq preset (more recent ones may certainly contain the most detail - but in a mix, there may be more to that equation than total zoomed in detail and a particular piano might just be perfect even if not the latest.. but over time they all improve and updated along with the engine), they all 'shine up' brilliantly in terms of recording/producing them although we can have our favourites and fav. pairings. If you do some things in a relatively unique way, it might become what others want to emulate.

For me, Pianoteq is by far and away the best 'like a real piano recorded in studio' to start to work from - no already over-produced saccharine settings to stop you from going in any direction you want to go with it, with some time taken to explore. I can say to anyone, you can enhance any aspect of a piano sound you need for any production with Pianoteq and a few reasonable tasteful plugin choices in your DAW - I'm hoping those who want to do this will take time to understand more about the various production values which might be required to do this to a high standard, as the many Grammy winners and nominees on the Pianoteq 'references' page may largely also have done - that's part of the secret of making better sound, keep at it and try keeping your artistic vision in mind, keep passion alive for your genre but maybe don't let it completely decide all the avenues you take along your way, as you draw knowledge and inspiration from the artists living and working and giving us their gifts of works and know-how to all, soak it all in - I'm not trying to do more than offer inspiration to anyone happening upon this, even if at least in the thought that, any one of us could become one of the fine artists listed on that page with some time, study, effort and application or a collaboration with someone in your world who may turn out to be your future producer. Friends can turn into important partners, treat everyone well and you'll increase your likelihood of gaining that kind of assist - and certainly don't ever fool yourself that you can't create something special - I believe we all can.

On other instruments coming to mind which seem suited to the piece you linked:

Pianoteq's harp might be a good instrument to consider for adding at some point (in case link is oddly formatted, "Mason Williams - Classical Gas w/ Deborah Henson-Conant")..

https://www.youtube.com/watch?v=0vXtywOlayc

the original for more of a production and mix comparison to the emotional and raw gentle version above (Classical Gas - Mason Williams 1968) .. just a personal note that the music can transcend the production tricks in various ways..

https://www.youtube.com/watch?v=8FvCviUW-58

Also I thought to link to some arrangements in terms of mixes - but couldn't think of a better thing than to point you to Nelson Riddle Orchestra, not because stylistically it matches because it doesn't and it's obv. in a different genre/era, is an example of packing in lots of action etc. (whereas your music linked possibly currently resonates well with a more laid back approach, or even more moody sparseness and so on with maybe some genre specifics you really want to respect) - but in terms of performing and recording incl. production values, some things are sort of timeless and interesting as observation points - I think there are many interesting things to glean and to treat yourself with in terms of mixing very big sounding instruments together beginning from this video (in case link is oddly formatted, "Naked City Theme Song - Nelson Riddle - 1962 - HD STEREO"):

https://www.youtube.com/watch?v=PaIipkrNU9A

Notice the guitar mixed to the right side, like your mix but they then usher the strings in on left and keep them contained rather than huge, piano also comes in left later but it's really small and tinky (and other instruments support etc.) there's quite a reverence given to the way bands/orchestras share 'limelight' for phrases - the reverb is insanely huge though, like it's all in a giant ballroom (but it's light on mud, inre. they had to rely more on rooms than we do now and the nice valve equipment did wonders with mid-range (in a way, opened it wider rather than pushing it up up up), which still drives me wild to consider how much more convenient all this can be with today's equipment) and the mids almost sizzzzzzle with a middle-range mechanic which kind of invites the top and bottom into the 'sonic party' - that 60s LP sound factor etc.. it's just a starting point and I'm not suggesting to copy this but style-note it perhaps and keep examining how our own mixes might have similarities or contrasts and all of it's useful; even if it's metal music that we make we can still learn from other eras and genres - mostly though, check the sidebar, suggested music is a click away (such as Riddle's almost diametrically opposites of this - like some harsh strings and electrics he also used).. thought it might be a few minutes of ear-rebooting fun nonetheless. There's something I loved about the orchestration he did for Linda Ronstadt (70s? haven't heard it for decades but it was a moment for me, 'wow that orchestra is so heavenly, soft and how do they do that?').

Side note: think of bass in centre, trebles to side.. you might get great mileage by learning some tricks about Mid Side processing or MS processing (not quite the same as MS microphone technique). Some mixing plugins make it a breeze to work with - it has a rich tradition and I rely on it in my personal ideals when making my Pianoteq 'sing' in my DAW.

Here's a certain kind of string mix I love too, (some woodwinds and other things help it along too) like up there with, say, Pavarotti's "Nessun Dorma"  timeless (Louis Armstrong - What A Wonderful World (Original Spoken Intro Version) ABC Records 1967, 1970)

https://www.youtube.com/watch?v=2nGKqH26xlg

It shows how strings can be present, but not hitting you in the middle ear - examine the subtle motion all the gentle transference from bass notes to trebles can elicit - I don't think I'll ever not be in awe of this and other productions/music which kind of hits us in the eternal 'feels' that way.

What I'd add about strings is that you can elicit so much more emotion by backing them off and considering the octaves - more depth in bass (cello to contra bass) paired with high strings with support harmonies fortified gently by viola etc., not so much need to intensify the higher violins if structure is deep - then guitar keeping rhythm and interesting modal changes within a fairly shallow EQ range, with piano underpinning then occasionally highlighting - but that's almost what I hear listening already.. it feels not far away to get it the way it will work better. I guess, the main trick in using modern string sounds (VST, sampled or synth) is to avoid one hand 'chords', by spreading triads across octaves (shuffle bass tonic for emotional vibe).

I suppose I could link too many things to the point of diluting the notions built in above, but this orchestration is a phenomenon - and I can hear something like this richness really being possible for your mixes and genre (Breakfast at Tiffany's Opening Scene - HQ)..

https://www.youtube.com/watch?v=1JfS90u-1g8

Providing a key instrument which is brighter than strings (maybe some toppiness on guitar might do it) can help put even the high strings in context.. I love how the high strings come in but you still hear the piano arpeggiation 'un-swamped' etc. Very instructive - I think I can imagine your music with this dimension and I'm confident you can leap over your current mixing dilemma by breaking things into more tracks (like orchestration, rather than 'strings' in one) - I have faith based on your already original and delightful instrumentations and choices of harmonies, melody etc.. it's seemingly all there - keep recording and mixing and it will take form

Another terrific recent composer to show us all how emotion is made with an orchestra.. (Ennio Morricone - Musique film - Il etait une fois en amerique 1984 Friendship And Love)

https://www.youtube.com/watch?v=LqFpLejxuJA

Maybe a fav. by Morricone, for piano, orchestra and voice - note the piano and orch. do not fight for dimensional presence - partly because with all elements toned down, there's more space to breath into (without a better way to express that).. (Ennio Morricone 'Intimamente' La Piovra 4)

https://www.youtube.com/watch?v=MWTC9kMPs6Y

Even at low volumes, it's the narrative 'arc' of stirring the senses with hints of 'something emotional and special's imminent arrival' for us.. then the swelling (like your change in "Tempest" - great effect you did this in that way I feel).. then a kind of settling of memories of the now 'past tense' - and you could go anywhere you want with that kind of arc in mind for any piece you imagine. You can hear the various parts of the orchestra kind of summarize our human emotions as they talk and evolve throughout.. a hint of promise, some more pensive moments, a kind of plateau then 'choose your own ending'

There could come a time when your recordings could have more hands involved, like producers, sound engineers, even art directors or sound designers, depending on the direction things go and what you choose, but it's always beneficial to be able to DIY, even if you're heading into a label deal it can help you choose your collaborators more wisely (try keeping control without some good knowledge of the recording process, and this is where a lot of money can be kept on your table) - I'd recommend it for anyone playing piano or guitar or vocals - being in more control in that process will be helpful in any musical journey in life, artistically and monetarily.

In the rinse it's always best keeping true to our personal artistic vision and experiment in the end, to find the things we love best. Plenty choose the easy sounds, the typical genres, the well worn tactics - but I think the highest form of musical connection/magic/lasting enjoyment etc. comes by way of transcending these, (kind of like, knowing the rules, not ignoring them but sorting how you order them around in your own work) and I think you're doing that for sure - and taking 'the good' from all sorts of genres can elevate your own chosen genres - lovely style connections are all around us for the taking, and the mystery evoked and so forth, makes for an exciting set of possibilities and I wish you and the Blue Arrows every success

Wow...that was really interesting...thank you

Thanks Qexl,some really interesting info there,really inspiring
I do usually monitor on my headphones as I'm usually doing this stuff early morning and don't want to wake my wife.
Funnily enough i just bought a new (2nd hand ) set  as I was having issues with one side dropping out but as Im writing this I think my monitors are the problem.