Mixed MH Photo period ??

[blstravler]

I just purchased a new 180 and have VHO and 3 MH 400's.

I would like to mix the photo period for the MH so that they do the following-

1030am VHO on
11am MH on
2pm MHoff
4pm MH on
7pm MH off
830pm MH on
10pm MH off
1030pm VHO off.

Any comments or concerns, any one ever try this?

FYI I am trying to bring the heat of the water down just a little.

Regards-
Keith

[grimmjohn]

You can do it..but there has been discusion about whether or not this cuases undue stress on the bulb?

[blstravler]

Do you think it would cause a shorter bulb life?

Also do you think it would hurt the coloration of the SPS?

TIA
Keith

[grimmjohn]

Theres a thread in the SPS forum called "run a short metal halide photoperiod" or something along those lines..it was discussed that maybe SPS just needed short (30-60mins) intense lighting bursts to photsynthisize followed by a lower intensity "maintance period". Many discussed better coloration after shorter photoperiods...but they were super-low nutrient BB tanks and it was speculated that the corals were lightening up to much from lack of nutrients for the zoox, and the shorter lighting period helped them darken up again.

About the bulb life, I think it's been brought up a few times...but nobody really knows...it just seems intuitive that the more often you turn something electrically powered on and off the faster you wear it out (this probably stems from the reason all our moms always gave us when we were doing strobe lights with the bedroom lights..."you'll wear it out..it only has so many times it can start up") () : )

Cheers,

grimmjohn