Hot Tub Filter Cycle Timing - Night only?

[Trilitheum]

Seems to be lots of variations on filter cycling between brands and online these days. My spa has a Balboa VS pack, which only allows the choice between 1 day cycle, 1 night cycle, or 2 cycles 12 hours apart. The default is two cycles 12 hours apart, 2hr duration.

My question is, is it advisable to go to 1 night cycle for 4 hours, which leaves the tub with no flow for 20 hrs and the does the filtering and heating all at once?
Reason I ask is we have time of use electricity and the night time rates are much lower than the day. Without being able to alter the time between cycles (locked to 12 hours) with 2 cycles a day, one cycle will always be in the high electricity rate zone. The one cycle would be the same filtering time (4hrs), my only concern is the how long the tub will sit with no flow at all, compared to the 10 hrs no flow with the two cycles a day. Does anyone else use night cycling only? any water quality issues?

Thanks!

 

[RDspaguy]

Does your spa have a 24 hour circulation pump? Do you know what model the control is?
Low speed pump is usually pretty low power usage (approx 3 amps), it's the heater that costs you (24 amps). If it has an ecenomy mode it will only allow it to heat during filter cycles, which could make quite a difference.

 

[Trilitheum]

No 24hr pump, just the main pump runs on low speed. It's a Beachcomber SST-10 which is a re-branded custom Balboa pack, but looks to be something like the VS501, 4 button top panel, basic controller/lcd.
Yes, it has economy mode, so the idea was to have it filter and heat around when we use the tub, then continue to filter into the night, then shut off until the next night 20 hrs later, opposed to running the next morning during peak electricity rates ~12 hours later, but this would leave it idle for 20 hours, which was my only real concern if this was too long to maintain good water circulation and quality.

 

[RDspaguy]

I couldn't say for sure, having never tried myself. I would guess it will not be a problem. Give it a try.

 

[Trilitheum]

That's the plan, was hoping someone would have been doing this for years and say no issues!
Worst case I guess drain, flush, and go back to the old schedule if the water takes a turn.