how many hours to light FOWLR and REEF tanks??

[Mooch28]

Hey guys, as someof you know by reaidng my journal, ive started a 110 gallon Reef tank. Will be SPS down the road, but for now mostly FOWLR.

My question is this. How many hours should lights be kept on?? I only have a 4 x 65 watt PC light for a total of 2.4 watts per gallon, and the tank is high (30 inches). I know for freshwater, the reccomended hours are 10-12, but what about for FOLWR systems??

And what if i start adding coral like sps, lps, softies, etc, is lighting hours the same or should they be decreased??

I do have a fuge that will have a reverse photo period, so please keep that in mind.

Thanks, you guys are awsome.

[Blinky]

On my reef the photoperiod is 12h:
1h actinic only
10h actinic + daylight
1h actinic only

On the FOWLR it's 14h (so we can watch the fish longer in the evening):
1h actinic only
12h actinic + daylight
1h actinic
3h moonlights

I use timers so the fish have gotten used to it, and the corals even start to 'get ready for bed' before lights out. I think 12h is enough, and some people with MH lighting run PCs for 10-12h with the MH on for about 6h in the middle of the day to mimic the time period of intense sun in the tropics. If you're running the fuge lights on a reverse photoperiod, I'd do 12/12.

[mysis]

A photoperiod of atleast 9 hrs is needed for all corals, anything over 9 hrs is not used for the production of zoo algae (needed for corals). so the required amount of light for corals is 9 hrs, but most normally run actinics for 30 minutes in morning and 30 minutes in afternoon, creating a photoperiod of 10 hours, which is supposed to be best.

[Mooch28]

ok got it guys, thanks.

I think i'll go 12/12.

Just one thing guys, why run actincs for an hour first and an hour after day lights?? Is their some benefits to doing this??

[mrsdorothy]

It givies the fish time to adjust to the light before the bright lights hit them.

[Blinky]

I just got a heads-up from someone over at reefcentral, who told me that with a lot of light (and a long photoperiod) on my tank, I'll likely get a hair algae outbreak soon despite having lots of macro to suck up PO4 and NO3. Just wanted to add that here - I'm still very much learning, so it's entirely possible that the light type/schedule I posted above won't work on my FOWLR for long and I'll reduce it by 110W and 4 hours or so.

[mysis]

Yes fowlers will suffer with longer light periods, as there is not point lighting them up for 12 hours or so. 10 hours is maximum, any more and hair algae will start to grow like a weed, unless you have no phosphate and no nitrate. When you do decide to get corals, keep you lighting at 9 hrs, as i said above thats the total requirement they need.

[Mooch28]

Yes fowlers will suffer with longer light periods, as there is not point lighting them up for 12 hours or so. 10 hours is maximum, any more and hair algae will start to grow like a weed, unless you have no phosphate and no nitrate. When you do decide to get corals, keep you lighting at 9 hrs, as i said above thats the total requirement they need.

Ok thanks guys.

Well im getting an Ro/DI unit, so my nitrates and phosphates should be as close to zero as possible, but stocking and skimmer production may change that. Rathern safe then sorry. Last thing i want is a major algae out break.


Anyways, thanks.

[jacobus]

i have a question.. ( i dint know about photo periods) my lights are usually turned on from the evening(5 - 6) to the next morning say around 8 a.m my room doesnt get much sunlight and the tank isnt near the window. but im not getting hair algae growths or the film algae on the tank surfaces ... does this mean that my water parameters are good, or am i low in something ? its a fowler for now .. but im very interested in making it a reef. the tanks been up for about a month or so. thing is i believe i got the wrong info from my lfs about starting up my tank. i have problems with my pH lvl (it drops overnight), but the lfs told me i could already add fish .. and so far i have no problems with the fish and even my anemones from my older tank. i tink my pH problem has gone away, but i recently ran out of pH tester.. ( dont worry im getting more later today) but could this be a problem ? oh and ive been using kalk with my top ups to solve the pH problem.

[mysis]

Well, it sounds as if your parameters are good. can you tell us your nitrates and phosphates, normally algae is grown because of them. Also is coralline algae growing? And are you saying that in the daytime you lights are off, but a night they are turned on? if so i would recommend changing the time of your lights, the fish and corals should have a period of darkness, and the lights can be turned on at say 11 AM, and then turned off at 8 Pm or maybe a bit later. Otherwise the anemone and fish may get stressed.

[jacobus]

i just noticed today .. but there are some bits of plant life growing on my LR.. it sorta looks like sea weed.. like a fern or something ... umm my room is dark in the day and the tank is placed in the middle area so a minimal amount of light enters the tank.

[mogurnda]

My actinics go on at 830a, off at 10p.
Halides on at 2p, off at 9p.

As far as the usefulness of various photoperiods, you have to consider intensity as well as time. I have seen studies using photoperiods from 10-15 hours, and the effects on coral growth very much depended on intensity. Keep in mind that fish and corals live with a 12 hour photoperiod in the tropics.

To be un-diplomatic for a moment, I find the loose talk about photoperiod and algae blooms to be a bit disturbing. I would be a lot more comfortable if someone were to point to a systematic study showing the effects of photoperiod on algae growth in reef tanks.

Jacobus, your setup sounds fine. If your daytime is their night time, that should work. It may be hard on the animals if they ever have to get jobs on the outside. pH normally drops at night, due to decreased photosynthesis, although it's kind of surprising, since your lights are on at night. Even with a reverse photoperiod in the refugium, mine varies by about 0.2 over the course of the day.

The fern-like thing is hopefully a macroalga that will be decorative and healthy. It may be bryposis, which is not so desirable, but we'll have to see what it starts to look like.

[jacobus]

hmm well .. its the same sorta algae that i bought from a lfs for my old tank ... so it should be good .. umm.. morgunda .. i dont understand what u mean about my reverse photoperiod ..

[mogurnda]

Maybe it's my misunderstanding, but I read from your post that the lights are on at night and the tank is dark during the day.

[Blinky]

To be un-diplomatic for a moment, I find the loose talk about photoperiod and algae blooms to be a bit disturbing. I would be a lot more comfortable if someone were to point to a systematic study showing the effects of photoperiod on algae growth in reef tanks.

Good point, sorry about that Dave, no more loose talking :). I wanted to post and just mention that someone had told me what I was doing might not work because I didn't want Mooch to follow what I was doing and then end up with problems. The person who told me I'd end up with a HA bloom was speaking from their own personal experience, they had nothing else to back them up. Apparantly they had a setup 'just like yours (mine), Caulerpa and everything' and zero N and P but HA moved in and took over. Thinking about it now, it's silly to think that an extra two hours of light could be the sole cause, obviously there were nutrients coming from somewhere.

[mogurnda]

I am actually feeling bad about that rant. Sorry. I was reacting to the general tone of the thread, which made it sound like extending the photoperiod a little bit will result in stress and disaster. Actinics have been on 13-14 hrs/day for years in my tanks, and I see no correlation with stress or algae blooms. However, I did a little reading this morning, and most authors do recommend 12 hours max.

[DansMarineTank]

Nice Avatar Dave! why not make 10 louder?

[jacobus]

just another question .. about the watts per gallon thing.. just how much should it be ?

[Mooch28]

just another question .. about the watts per gallon thing.. just how much should it be ?

watts per gallon doesnt really apply in salt. It's more about intensity and reflector quality.

MH are best for deep tanks, and high light corals.

VHO are second, but not as effective as MH. Good for low-medium light corals.

T5 and PC are pretty much in the same league, and good for low-medium light corals. However, T5's if they have the right reflector (Tek light) can be good enough for high demanding corals on tanks that are not that deep or large. 100 gallons max from what ive read.

[mysis]

Your T5 thing is wrong, i have seen acros and clams grown in a 220 gallon with t5 lighting and it was perfectly fine, set up for about 2 years and the owner recently went for a change in lights, no problems at all.

[Mooch28]

Your T5 thing is wrong, i have seen acros and clams grown in a 220 gallon with t5 lighting and it was perfectly fine, set up for about 2 years and the owner recently went for a change in lights, no problems at all.

really??

How many T5's??

allways something new to learn, gotta love the hobby!! :D

[mogurnda]

Nice Avatar Dave! why not make 10 louder?/blank stare/...this one goes to 11...