Alk and shrimp/crabs

[earlybird]

Is there any relationship between alkalinity levels and shrimp/crab deaths? Since May I've lost 1 peppermint shrimp, 1 cleaner, 1 fire, and 1 emerald. I though I was starving them but I spot fed the shrimp when I fed my fish. My water has remained constant 0 amm and trite, close to 0 trate and phosphates. Cal 400, alk 11 dKH, mag 1275 but yet pH 7.8. The fire and emerald were most recent and I have an unknown fuzz like growth on areas of my rock that seemed to accumulate on them, possible cause

29g, 10g sump, overskimming, 45lbs LR, 2" LS, 76.5-78 degrees, 31x flow rate, 2 false percs, 5 astraea, 12 hermits, 10 nassarius give or take 2.
Could be temp but I'm in Fla and do have heaters just not in. Just came to me so when I'm done here I'm going to put my heaters in.

 

[zeroc]

do you keep an eye on your temp? but you might want to look into possible copper in the water. Do you use RO or just tap?
and is that it for fish? just the two percs?

 

[earlybird]

I use RO and my snails and hermits seem fine. Yep just 2 percs.

 

[teen]

whay are you worried about ALK? does it tend to swing?

 

[worldwide zoo]

Shrimps and crabs are very sensitive to specific gravity(salt level) changes. In a small tank, if you allow evap to go without topping off with fresh R/O for more than 1-2 days and then top off with say 1 1/2-2 gallons of fresh, the change is too great and osmotic shock kills them. Top off daily and keep salt levels very stable. By the way they are more sensitive to salt levels drops than they are to spikes.

 

[earlybird]

Originally Posted by teen
whay are you worried about ALK? does it tend to swing?
No it's within normal range but on the high end and I was just trying to determine the effects of high alk. It doesn't swing.
I'm a top off freak. I top off in the morning, when I get home from work, and before bed. If I leave it for 24hrs it only raises from 1.025-1.026.