Height for t5 fixture and photoperiod

[michaum]

Hi I have a low boy frag tank setup for 1 month now and i am wondering if my t5 fixture is too low or too high it hangs 24 inches from water surface and if my photo period is ok here is a picture:

Here is what i have in the fixture:

60 Inches fixture
8x80 watts

6 x ATI Blue Plus
1 x ATI Actinic
1 x ATI Aquablue Special

Frag Tank:
48″ x 24″ x 10″ Low Boy tank

Photo Period:
9 hours total

9 hours --> 3 Blue Plus + 1 Actinic
6 hours --> 3 Blue Plus + 1 Aquablue Special

Thanks for all your replies and help.

 

[jayball]

If all the coral is reacting well than you can try to lower it by an inch a week or so, just watch for an adverse reaction. Personally I would try pulling two of the bulbs and dropping it by 6-8 inches as you are dumping a bunch of light outside that tank. This would only be with access to a PAR meter though so you could match the intensity.

 

[mcgyvr]

Too high IMO...Id run it at maybe 14-16" above that tank..
9 hours is fine..typically 6-8 is all you need though..

 

[Big E]

Way too high.............My frag tank is 48x24x12 and my 6x48 ATI fixture is 10" from the water surface. The water surface height is approx 10" from bottom to top.

The acros that color best are on a 4" high rack and directly below the center of the fixture, so they are only about 6-7" from the bulbs.

I run 7 hours all on, all off.

I would lower it over time, not all at once. For example go to about 15" and then in a few weeks go down another 2" ect. Once you start getting closer maybe down down an inch every two weeks.

I see what looks like acros on your rack, so they should be fine........... if you decide to add some LPS you may have to watch them to make sure you don't bleach them.

 

[michaum]

Way too high.............My frag tank is 48x24x12 and my 6x48 ATI fixture is 10" from the water surface. The water surface height is approx 10" from bottom to top.

The acros that color best are on a 4" high rack and directly below the center of the fixture, so they are only about 6-7" from the bulbs.

I run 7 hours all on, all off.

I would lower it over time, not all at once. For example go to about 15" and then in a few weeks go down another 2" ect. Once you start getting closer maybe down down an inch every two weeks.

I see what looks like acros on your rack, so they should be fine........... if you decide to add some LPS you may have to watch them to make sure you don't bleach them.

ok at 24inches fixture height i did a par reading and dead center im getting 370 par front of tank is at 270 par and rear of tank is at 330 par the reason the front and rear are not the same is because i have put the fixture more to the rear of the tank so the the front would have less par. So by lowering the fixture from 24" to 15" wont i almost double the par? so the midle would be something like 740 par that would cook the corals no?

Thanks.

 

[Big E]

Hmm, that doesn't sound right at 24". What were you using to test par?

I measured everything today and snapped a quick pic...I was off slightly on my comments above

Here is mine. At 12" from the bulbs it's 350. That is at the upper rack in the middle.
ATI Sunpower 6x48 at 9" above water line.

Water from top to bottom 11"

I use a Apogee 200

 

[michaum]

Hmm, that doesn't sound right at 24". What were you using to test par?

I measured everything today and snapped a quick pic...I was off slightly on my comments above

Here is mine. At 12" from the bulbs it's 350. That is at the upper rack in the middle.
ATI Sunpower 6x48 at 9" above water line.

Water from top to bottom 11"

I use a Apogee 200

Using Apogee
8 60" t5 bulbs 640 watts total.
Fixture at 24" from water line
measuring par center of tank
Par mesured at 364
Tank 10" deep rack 3" high so mesure of par 24" plus 7" water depth

Yes what i said is indeed right see pics:

 

[mcgyvr]

well.. if nothing else this shows how overkill an 8x80W fixture is on a tank of your size
So much light being wasted out the side because its up so high..
You could have easily gotten away with less bulbs/less width and saved a few hundred watts of energy not to mention bulb replacement costs,etc...

 

[michaum]

well.. if nothing else this shows how overkill an 8x80W fixture is on a tank of your size
So much light being wasted out the side because its up so high..
You could have easily gotten away with less bulbs/less width and saved a few hundred watts of energy not to mention bulb replacement costs,etc...

frankly i don't care of wasted light, or bulb cost or energy wasted the light fixture was practically given to me so my question is will it still be good for my tank and grow corals even if the fixture is overkill for my tank?

 

[michaum]

well.. if nothing else this shows how overkill an 8x80W fixture is on a tank of your size
So much light being wasted out the side because its up so high..
You could have easily gotten away with less bulbs/less width and saved a few hundred watts of energy not to mention bulb replacement costs,etc...

I forgot to mention, or if the wasted light has a negative effect on coral growth or not?

Thanks.

 

[mcgyvr]

frankly i don't care of wasted light, or bulb cost or energy wasted the light fixture was practically given to me so my question is will it still be good for my tank and grow corals even if the fixture is overkill for my tank?

:facepalm:
Its fine.. Just leave it where it is..

 

[Big E]

The one thing I see you have wrong is from the one pic you have the Apogee set to "sun".

It needs to be on "electric". Also measure it with the flow on.............the reading will jump around some but it's going to probably read less.

Here is another tank 10x54W 5" above the water line

I'm not a expert but from what I know you should be getting similar readings, especially dead center. More bulbs only creates better coverage it really doesn't produce more par.

The watts of the bulbs is only higher because the bulbs are longer.

Probably the best thing to do is to use the corals as your guide. If they grow slow or don't have vibrant colors you can move it down.

On another note, if that is a separate system you're going to have to get some fish in there. This is really important and your going to have problems with growth and pale corals if you don't.