This encounter is in dire need of a revamp to make it more accessible. As it is right now, it's mostly only doable in a tightly controlled pre-made setup.
It is setup to permit lvls 41-51 and 20 players maximum. That should be addressed to begin with, it becomes exponentially more difficult the more players are allowed in the encounter, in large part due to how the Fragment spawn mechanic is setup.
The Crystaline Entity spawns Crystaline Fragments every set HP % interval, the more ships and thus more DPS is being thrown at the entity, the faster its HP drops and the faster it spawns Fragments, thus if fragments aren't dealt with appropriately you end up with what happens quite often, a sea of Crystaline Fragments flying around destroying everyone.
PUGs cannot compensate for such a mechanic, it's really only feasible in a tightly controlled pre-made RAID/Fleet/Guild whatever.
However that is only part of the problem, once the Entity's HP drops below 33% it spawns Large Crystaline Fragments in place of the Crystaline Fragments, the Large Crystaline Fragments Shatter if they are destroyed by any means, be that Torpoedo's, Beams, Hand slapping, Mines, Farts, head butts or they touch a player ship, carrier pet, mine, photonic fleet or any other imaginable way.
Once a Large Fragment shatters, it spawns 3 Small Crystaline Fragments, these fly back to the Entity at high speed and heals the Entity for a considerable amount each. This is usually where most PUGs never manage to get past, because people either blow up the Large Fragments, get blown up by the Large Fragments, or any other combination and fail to handle the Small Fragments in time before they return to the Entity.
Contrary to popular belief, hitting the Crystaline Entity with any weapon, of any kind, does NOT heal it.
The encounter could do with being restricted to lvl 50 to begin with, and a maximum of 5-10 players with the Entity's HP scaled down appropriately.