My helpful tip is take it back before it wipes out your tank. It is absolutely doomed to death by starvation as the fact it's brightly coloured and has those long branching 'things' means 1. it's toxic and 2. it's a filter feeder not a detritivore.
Unless you're prepared to grow fresh phyto or buy it, or cultivate rotifers or other nano plankton it's doomed to die in your tank, and that bright colour would have me worried.
I strongly doubt you will be able to feed it with phyto/nano plankton sub foods unless you can get the chilled stuff, and then whisk it down to stop clumping.