Downsides of a 15 hour photoperiod?

[Andy V]

Ignoring the economic costs, what are some of the downsides of running a 15 hour photoperiod? I want to do this so I can feed fish 2x a day, but I do not want to run a reverse light cycle either. Assume that algae is not an issue either. Thanks!

 

[MPevine11]

how would algae not be an issue?

 

[MikeG]

photo inhibition?

 

[Andy V]

how would algae not be an issue?

If you export nutrients, have good husbandry, run GFO, and carbon dose, you will have little phosphate for the algae to feed on.

 

[jenreef]

If you export nutrients, have good husbandry, run GFO, and carbon dose, you will have little phosphate for the algae to feed on.

yea but they would feed on the light the dont only need nutrients to feed off of like hair algae.

 

[jayman10134]

I would see no issue with a 15 hr photo-period when disregarding algae. I have to ask though, why can't you feed your fish twice within the normal 8 hr photo-period?

 

[Andy V]

I was under the impression that algae could not grow without PO4, but the quick research I have done says it can as some of you stated. Apparently no PO4 just slows the rate of growth dramatically.

 

[jayman10134]

I was under the impression that algae could not grow without PO4, but the quick research I have done says it can as some of you stated. Apparently no PO4 just slows the rate of growth dramatically.

Slow growing algae would be controllable with tangs, urchins, and snails.

 

[Andy V]

I would see no issue with a 15 hr photo-period when disregarding algae. I have to ask though, why can't you feed your fish twice within the normal 8 hr photo-period?

Because I leave my house at 6a.m. and don't return until 8 or 10 at night during the week. I am awake in the house for basically three hours during the week...an hour in the morning and two hours at night.

 

[jayman10134]

What about 2 4 hour photoperiods, or even 2 5 hour photoperiods? I would say go for the 15 and let us all know how it works. Also, you could have a 5 hour dawn with actinics so you could feed but not fuel the algae to much with light. Of course if you do it increase it by small amounts so you don't come home to cooked corals the first day!

 

[gweston]

Because I leave my house at 6a.m. and don't return until 8 or 10 at night during the week. I am awake in the house for basically three hours during the week...an hour in the morning and two hours at night.

I am running 12 hours myself at the moment. 8:30am to 8:30pm. I feed when I leave in the morning, and I feed after I get home at night. I'd prefer to keep it to 8 hours, but time just doesn't allow. One condition on having my fishtank was that my wife didn't want to be tied to feeding or taking care of anything. On occasion, yes I can get her to check on something or toss something in... but I can't push my luck

My phosphates and nitrates are at 0, and I have been dealing with some red slime (cyano) algae. A few small spots. I am pretty sure it is due to the photoperiod. I started dripping Kalk and am moving to dual reactors for GFO and Carbon. I have been using filter socks in the sump. While my parameters are undetectable, by increasing flow and making those additions. I am -hoping- it will help cut out the red slime.