Hydrometer

[Parker]

What do you have to do to get a decent reading out of these things?

I have a 29 that I set up 24 hr's ago and still every reading I take is different. Taken from the left it's low, taken from the right side of the tank it's good.. Take another reading it's higher..

It's Instant Ocean hydrometer..

The tank is free of inhabitants, well except for the live rock..will possible salinity issues cause the live rock to die off?