Your frogspawn may have doubled in size to look for more light. It did not double the number of heads which. Is a truer sign of growth. You can switch to a 14K from the actinic, but you will lose almost all your blue. Tis will be great for the coral, but you might not like the more brown look of your tank.
If you spend a lttle more or wait to find a used Tek light you will be very happy. A fixture with individual reflectors will put out a very significant amount more useable light than the one you are looking at, which I bet has one rusted piece of metal behind all the lights. It's not worth buying IMHO
as you will look to upgrade from that soon.