I have read that frogspawn likes low flow. I added one to my nano tank over the weekend with mh lights and it wouldn't open that much for a few hours. I checked my salinity and bumped it up a tad to 1.026, moved it from middle less lighted area of bottom of tank in sandbed to right side of tank in full light, turned flow down from high flow to medium flow and there on the right side in high light he is in low flow. one day later bammm.. open 10 times the size and is georgeous. I also add stronium, trace elements, calcium.
if you do a google search you can read more than you want to know about frogspawn.