Keep a spare O2 tank and oxygenate before you pitch

I use one of those disposable oxygen tanks to oxygenate my wort and have always though at $10 a tank I should always keep a spare around. My first tank lasted 15 5 gallon batches, this new one only last five and at a horrible time.

I brewed a lager this past weekend and chilled it down to 44 degrees, had made a starter with a stirplate the previous week, chilled it, and decanted it. It was time to pitch my yeast this morning before I left for work. I usually oxygenate first, then pitch the yeast so they have plenty of oxygen when they first hit the wort. I guess because I hadn't had my coffee yet I pitched the yeast, then remembered I still needed to oxygenate. Only problem was that when I turned the tank on I only got about ten seconds of good aeration then it slowed to a trickle. I left it in for at least a minute and a half at the trickling rate but now I'm afraid my lager wort doesn't have enough oxygen.

I'm wondering if I should go to the store today on my lunch break, pick up another tank, and give it another does of oxygen tonight. I think it will be ok since I pitched at 44 degrees the main fermentation cycle will not have started yet, usually takes my lagers a few days to get going anyways.

Any thoughts?

Oh and the reason I say oxygenate before you pitch is that if I would have done that I could have just put my yeast starter back in the fridge and waited until tonight to pitch after I picked up another bottle.

It's a toss up. Don't see that you will do any harm, but it goes against my nature to tinker after getting the fermentation going. To me it is a bit of Voodoo when we add random amounts of Oxygen without a real system to measure how much we put in. Having a backup tank is a good idea.

I always re-aerate my big beer about 10 hours into fermentation and never had a problem (I believe it has really helped me hit a lower FG). If the fermentation has just started I say hit it with another round of o2!

Great, think I'll give it a try. If it was just a low gravity ale I wouldn't worry about it but since it's a lager that will already be temperamental I figured another burst of O2 is probably needed.

I usually do a minute when I first pitch and then a 30 second blast after 12 hours or so. Works great.