How big are the tanks ?
I would really not recommend that you move any fish inside a tank with water.
Its very very difficult, – the water gets in so much movement that it will splash out of the tank even theres very little in it.
When I moved 3 years ago and also had a lot of small tanks and small fish and even small fry, I caught all fish that I could catch, – but I do remember I did transport a few tanks with water, – I cannot remember if this was because of not wanting to take things out or if it was because I was unsure if there was any tiny tiny fry. And I also cannot remember if it went all right, I think it did though 🙂 – but I would really recommend that you catch all visible fry 🙂
But what I did was to empty the tanks down to maybe 5-10 cm water left and then put something in the tank that prevented too much movement of the water, like many plants or leaves (as a kind of lid)- but NOT anything that can rush around and break glasses. In fact all that needs to go out, because it will move once you drive and break. If you drive with it open when you arrive there will probably not be water left in this tank otherwise.
And then of course go slow – real slow.
But in fact people are often really worried about catching parosphroemenus and especially fry, but my experience is that 1. it can be done and 2. it mostly goes well, – they are not that fragile.
You just need to be a bit structured 🙂 ..
I started by setting up some tanks in my new flat so they were ready, – then I took out all decoration in the old tanks, let the dust settle, catch the fish and transport them directly down to the new tanks. Or with paros – if you dont have this option, – they can really stay in a smaller container for a day, that will be fine.
The thing is to empty the tank in good time, – because theres often so much debrie, leaves and ‘dust’ that it takes time for the tank to become visible so you can actually see whats in there. But taking all out little by little, leave it to settle, catch a fish (then it all may become dusty again, then leave to settle again, catch another fish)
I often do this – also now, when for instance I have to seperate young from a tank, – its often impossible without stripping the whole tank. And I do that, and the paros have to endure some hours in bare tanks, which of course they dont like, – but I can assure you two minutes after they have got their ‘furniture’ back in the tank, they look happy again.
Theres also the option of ‘sucking out’ some water with a big hose (thats more if there are ‘invisbile’ fry there) or just pouring water from the tank into a transportable container. If theres very very small fry, this could be a way to get these along.
Anyway these are my experiences, maybe others have some good tricks 🙂