Calcium reactor C02 regulator question

[Poriferabob]

Hey everyone. As I've been doing for years, I re-filled my co2 tank at the end of last week. This time I noticed something a little strange. Upon hooking my regulator (carbon doser) to the tank to complete my "bleed test", the bottle pressure needle SLAMMED to the max position. I always open the bottle slowly to control this but even still it hit hard. So, I think my bottle was over-filled.
Now from what I understand, it is a 5-pound tank with a tare weight of 7 pounds. So I weighed it and it was around 15 pounds.
Anyway, to be safe I let some of the gas out of the tank and tried again. But now the gauge is still reading higher than it has every other time. (Normally around 800-900 Psi after a fresh fill)
So my questions are;

1. Is it safe to run this size bottle at the pictured psi or should I empty more?
2. is it safe to say my bottle was overfilled?
3. Did this possibly damage my pressure regulator?

 

[ca1ore]

I'm not sure that it is even possible for a CO2 tank to be overfilled since it is filled with liquid. Tanks left out in the sun can certainly over-pressurize. Was the tank hot or warm to the touch when you hooked it up? If it was, letting the cylinder cool down will restore normal pressure. Letting gas out of the cylinder won't help because the pressure stays the same until all the liquid is gone, at which point your cylinder is essentially empty. If memory serves, you are supposed to completely unscrew the pressure adjustment knob before opening a new cylinder. Did you do this (looks like you did)? If so, I'd imagine the regulator is fine.

 

[Poriferabob]

I'm not sure that it is even possible for a CO2 tank to be overfilled since it is filled with liquid. Tanks left out in the sun can certainly over-pressurize. Was the tank hot or warm to the touch when you hooked it up? If it was, letting the cylinder cool down will restore normal pressure. Letting gas out of the cylinder won't help because the pressure stays the same until all the liquid is gone, at which point your cylinder is essentially empty. If memory serves, you are supposed to completely unscrew the pressure adjustment knob before opening a new cylinder. Did you do this (looks like you did)? If so, I'd imagine the regulator is fine.

Thanks for the response. You are correct, and yes I did open the knob completely. Per the carbon doser instructions, you MUST do that every time. This is referring to the gauge that reads 0-15 and controls the actual amount of C02 being "dosed". So I know that gauge should be fine. Just concerned for the tank pressure gauge.
Your explanation regarding the temperature and inability to overfill do make sense to me. But the tank has been in my ac controlled house and not above 77 degrees.
If I can rule high temps and overfilling out, any other ideas or thoughts as to why it may be showing such high psi this time? I've done this maybe a dozen or so times before with this same rig and its never done this.

 

[ca1ore]

Hmmn, that is odd. How old is the carbon doser? Maybe something amiss with the high pressure gauge. Might be prudent to inquire with the aquarium plants guy. Perhaps it's nothing to worry about.