I did my third run with one of my Carriers to Colonia recently - that is, the 23k + from Bubble to Colonia.
But since was my third trip, I learned the tricks this time:
1 - all empty
2 - all module uninstalled
3 - all unnecessary ships "parked" in my carrier were moved to a station ( I only carried 2 Vett.s, 2 Cutters and a bunch of Chally and Cheffy.s, since those cannot be aquired in Colonia). And OBVIOUS, the 2 ships one MUST have in a carrier - the landing one, equipped with SRV. in case you need to land and grab some materials and, most important, the THUG BOAT - aka big & fast fully equipped miner ( in my case, the Queen Miner, the Cutter) - just in case, you know....
Conclusion - started the run with 6k Tritium in depo, at only 9000 from 25 000 occupied, and half trip I was to a nice limit of some 86-81 Tritium per 500 ly jump - I reached the Colonia with more than 2400 Tritium still available on depo ...
In the first trip I used near 6k Tritium. On this one, only 3600.