How high is too high ? T5 placement. ...

[Jonathan blackwood]

So I rebuilt my canopy and it will place my 6 bulb ATI T5's about 18 inches about the water. Is that going to be ok? I am planning on adding a secondary led system as well due to all the new space I created but as for now, will that be ok and have enough strength for my reef ? It will be on a 72 gal bowfront.

 

[Triggreef]

Lots of other factors to consider. Coral placement, type of corals, what they are replacing... From my experience with par meter and t5, they lose a good amount of par quickly and don't penetrate the water as far as led's. But its not all about par. Spectrum is more important. That said 18" is very high IMO I put lights as close as I can to the water without causing excess damage from the water.

 

[Sabellafella]

Depending on how high you keep your coral, keep the fixture 28-40 inches from your sand bed, have your coral under no less then 12 inches no more then 24 (acropora) directly under the dimensions of your fixturd. Could look at my build thread if you want a general idea as i took some par readings

 

[ngvu1]

Mine 6 bulbs 39W is 8 inches above the water surface. I felt, 6 inches was a bit close

 

[mcarroll]

So I rebuilt my canopy and it will place my 6 bulb ATI T5's about 18 inches about the water. Is that going to be ok? I am planning on adding a secondary led system as well due to all the new space I created but as for now, will that be ok and have enough strength for my reef ? It will be on a 72 gal bowfront.

I would try to get a light meter and take some readings....guessing is a sure fire way to fry corals or get some other undesireable outcome.

If you have PAR meter available, that's great, but they are expensive and quite a bit of overkill for this small purpose.

So consider downloading a $free [HASHTAG]#lux[/HASHTAG] [HASHTAG]#meter[/HASHTAG] app for your smartphone's camera and take some readings tonight! (While the app is downloading, go to your favorite major reseller and order a $15, delivered, handheld lux meter....the basic model everyone carries is the "LX-1010B", so you can search for that. Much better than the apps AND much safer to use around saltwater!!! )

See what the difference is between the intensity at the old height and the new. Big differences in light - whether increases or decreases - are typically pretty stressful, possibly leading to mortality.