I have two loaches in my 55 gallon freshwater tank. My parameters are 6.6 Ph, 0 nitrates, 0 nitrites, and 0 ammonia. 5 Discus, 2 Farlowellas, 4 Cardinal tetras, and 6 Black Neon tetras. The Loaches have been in the tank for about three months and have been doing very well. Now the bigger loach of the two is going nuts swimming back and forth across the long part of the tank very quickly over the last three days. Not like the other one which is acting normal. Any ideas? I've had loaches before but none have acted this way before. They are not very old one is about 1.5 and 2.5 inches. The type I am unsure these loaches are similar to the clown but more slim. The temp for on average should be what for loaches? Any help would be appreciated. 
