I have just bought an upgrade tank (84L) I plan to move my 2 platys, 3 Zeb Danios, 1 Hong Kong Pleco, 1 ghost Shrimp, 2 Apple Snails and 2 clams across (once they have recovered from their whitespot) to new tank in a few days. They are currently in a 35L. I have a few questions??

Can hong kong plec live with platys, I currently dont have a heater in my 35L (the platys were sold to me as Temperate water fish, didnt realise they were tropical?) They have been fine at constant unheated 18*/20* for over a year. I am planning to have a heater in the new tank so my question is -
will a hong kong plec be happy with water temp at 22* and will platys be ok with this too ???? Ive read all different on this??
Would the plec be ok in new tank as there is no green for it to feed on?
Would shrimp, snails and clams be ok in new tank as again no green or crud yet for them to feed on. Would Alge wafer be ok as a replacement??
Im planning on moving some of the old tank water over , all the plants and squeezing the olf sponge in to the new filter, will this help the cycle??
Any advice welcome, Thanks

Yes 22C will be OK for all your fish.

If you're not moving them for a few days put a few clean large pebbles in some dechlorinate water on a sunny winowsill and alse shoul grow on them. You can pop them in the tank as a food supply for the HSL when you move the fish over. The shrimps will probably happily eat algae wafers and you can supplement them and the Apple Snails with some lettuce of cucumber (the HSL Might eat those too).

If you won't be using the 35L, take the sponge an put the whole thing in you new filter along with the new media. Cut it up if necessary and just squeseze it any way you can. That will tranfer the bulk of the bacteria an help prevent ammonia/nitrite spikes or at least keep them to a minimum.