Really it's a case by case basis, plus it depends on what kind of dat you have. AT's and NGT's have really small mouths compared to the other dats and MIGHT fare a little better with smaller clown loaches. Either way there are no guarantees...
depends on the individual fish but my 8"-9" NGT can take 3" whitebait no probs as could my 6" indo as already said they have the slighlty larger mouths,i wouldn't risk it just in case
I wouldnt do it....If its hard for the dat to eat it will leave it alone but if it isnt then your taking a chance. I had a dat that tried so i just took out the loaches. Good thing i was watching at the time.
make sure the loaches are big enough. i would recommend 4-5+ inch because datnoids will eat depending on their mood. my 7 inch thinbar ate 20 clown loaches @ 2" so just to be on the safe side bigger the better.