Hi there, my pool light bulbs are ALWAYS burning out. Pool was opened yesterday. I check the two bulbs, one is out. Luckily I had a spare, I replaced it, then about 5 minutes late the other burned out. The housings are 18 years old and will be replaced in the next year or two along with the liner. 

New BulbOld BulbOld BulbOld Bulb
Anyways, the bulbs are damn expensive. 60W incandescent costs me $30 at the pool store! It comes with a gasket that goes around the bulb (they can be reused if they are still in good condition).

I found some bulbs that look almost identical to the ones I buy at the pool store. There is a slight difference on the back. Can anyone tell me if I can use these bulbs? They are philips. I found them at a store for $2.50.

I have attached images of the two bulbs (the dirty one is from the pool store), the philips one is the one in question. 

Thanks in advance.