I let mine run all night all the time. It ran all night last night and will run all day and night again tonight. The only thing it hurts is your electric bill.
Where is the PSI when clean? That will tell me where you need to be in regards to the pressure. Mine runs at 15 when clean, I backwash at 8 to 10 psi after that. It's gotten up to 30 before with no ill effects, but it wasn't for more than a few hours.
I tend to backwash until the water is almost clean, turn off the pump, put the valve back in wash mode, then wait 30 seconds before restarting. I've heard people (who may not know better) say to backflush for 45 seconds or so, and that's enough. I'm betting with your minute to 1.5 minutes, you are probably getting it. Either way, you need to know your baseline at clean to determine when to backflush.
If you can't afford the whole kit, go get at least the DPD chlorine test kit from tftestkits.net so you can accuratly measure over 10.
Where is the PSI when clean? That will tell me where you need to be in regards to the pressure. Mine runs at 15 when clean, I backwash at 8 to 10 psi after that. It's gotten up to 30 before with no ill effects, but it wasn't for more than a few hours.
I tend to backwash until the water is almost clean, turn off the pump, put the valve back in wash mode, then wait 30 seconds before restarting. I've heard people (who may not know better) say to backflush for 45 seconds or so, and that's enough. I'm betting with your minute to 1.5 minutes, you are probably getting it. Either way, you need to know your baseline at clean to determine when to backflush.
If you can't afford the whole kit, go get at least the DPD chlorine test kit from tftestkits.net so you can accuratly measure over 10.