Clown Loaches--sick?

I named them Skitter and Scatter, because they are neurotically shy.
They have developed a new hobby, or they are slowly dying, of laying on
their sides together behind a planter. Slightly worried. Last night I
assumed one was dying, then this morning when I went to scoop out its
corpse (sadly, because this is fast becoming my favorite species of
fish) it was fine. Now they are doing it again. Any opinions?

Jamie

55 gal, planted
3 watts/gal

2 clown loaches, approx 3"
3 angelfish, 1" to 3"
2 otocinclus
3 harlequin rasboras
1 betta, Tony