Steve - thank you very much for the reply. I have a few follow-up questions please...
1) Would you opt for the E. bicolor because of personality/aggressive, personal preference, better mix with the other fish, or other reasons?
personality. I rarely, if ever, express personal preferences
2) I neglected to mention that the 68 gallon will be a mixed reef - I don't believe any of the fish I listed are really coral nippers; is that correct?
please refresh my memory
3) Re the extreme answers, I meant as to the number of jawfish I could try to keep, but the substrate answer helps regardless. I still have 4 bags of southdown sand. I was planning on mixing that with crushed coral for both the 55 gallon with jawfish and the 20 gallon with pistol shrimp. Would that be suitable? What ratio of southdown to crushed coral should I try to achieve if it is suitable?
for both jawfish (especially) add some live rock rubble and "junk" shells. The ratio is difficult, I normally just eyeball it but maybe 1/3 crushed coral?
4) The jumpers... would eggcrate be suitable to protect against jumping? Or should I source some of the finer mesh that I've read about? eggcrate is useless. you need 1/4 mesh available from Lowe's or BRS reef supply or similar vendors who also supply framing materials
5) Can you please elaborate on the "two shrimp?" Is this to give the fish more options with regard to pairing with a shrimp? Or to hopefully have the shrimp pair up?
It is an interest issue. One goby can easily "manage" two shrimp but not the reverse. Two gobies need to be a bonded pair for multiple shrimp (and for coexistence)
6) My son would like to consider one more fish for the 20 gallon - is it fully stocked as is with regard to fish?
I would not add another fish
Thank you again!