Had to have a disaster sooner or later!! Help!

[hillbillyreefer]

Tank looked good last night at lights out at 11 pm. Looked good under the moonlights at 3 am. Lights on at 11 am this morning one clown missing one in rough shape. Tank is a JBJ nano cube 24 dx. Running chemi pure, carbon, no balls, sponge cleaned yesterday and removed this morning. Tank is almost ten weeks old, no problems, nice gentle cycle. Animals include 2 clowns, 1 psuedochromis, 2 open brains, 1 green bubble coral, numerous kenya trees, few polyps, 2 unidentified sps's, more GHA than I care to mention, Calupera (sp), other macro algaes. There is also a whelk in one of the back chambers, banished for attacking snails. CUC about 1 dozen various hermits, not sure how many nassariuss snails, 3 peppermint shrimp one molted last night.

Tank Parameters: This morning
Nitrate:less than 5 ppm (api)
Nitrite: less than 0.3 mg/L
Temp: 79.5

Last nights tests:
Nitrate: less than 5 ppm (api)
Nitrite: less than 0.3 mg/L (hagen)
Temp: 80.5 F
pH: 8.2 (electronic, calibrated 3 weeks ago)
Salinity 1.023 hydrometer, 31 refractometer.
kH 7 (low)
Cal 300 (low)
Phos 0 (api)

Tank is fairly stable. I dose with Calxmax 2 times per week and did dose it last night.

Water change was done Thursday. I'm mixing up another batch of salt as I write this, heater in bucket and it's sitting on the warm woodstove so should be ready in about 1 hour. Next problem I don't have enough old salt to finish the batch so will have to mix salts, more stress I know but there is nothing I can do about it.

Only other hint I have is one of the brains was swollen to double it's normal size yesterday, not sure what that means if anything. Looked normal at lights on this morning and still looks normal.

Second clown has died while typing this up.

Any ideas would be helpful.

Thanks
Brad