DIY LPS feeding protection?

[Calm Blue Ocean]

I've got a blasto that hasn't been feeling well so I've been trying to do some supplemental target feeding. Problem is that he's a super slow eater and the odds that either someone takes his food or he doesn't have a good grip by the time the pumps come back on is pretty high. I looked at some mushroom boxes but most are either way too big for my needs (it's just one head) or would allow too much flow to get through. Any good DIY solutions for some protection for this guy while he eats?

 

[shwareefer]

Feeding at night should help.