Congradulations on the clams! it depends on the size of the clams, if there all real super small, yep I would use the bowl tank and feed DT's or better yet culture your own.... im sure you know the technique, take a clean plastic cup or bowl...submerge it in the tank...place the unatached clams in it....then take the container out of the water making sure there is no direct contact with air, simply dont let the air touch the clams....then add enough DT's to give the water a slight green tint...come back later and put the clams back where they were in the tank making sure once agen they dont have air contact....i usually leave my baby maxm out for 15minutis to 30 mins...or whenever i remember to put him back the water should be back to normal coloration.....or you could use the pop bottle top method...just drop the cut pop top bottle over the clams add the phytp with a syrenge or turky bater that way...and if the clams are large in size then i would feed the dts directly to the tank...dont add to much at first the stuff and up your nitrates and phosphates...but your pod population would enjoy the DT"s