How much light is too much?

[3rdMoon]

I’m coming to the end of my “rookie” 75 gallon mixed reef tank build. Mostly fish, zoas, LPS (also a test run with a few SPS hopefully) I’m looking at an 8 bulb T5 HO fixture with 2 channels (4 bulbs each) It’s not sexy or sleek but it’s got good reviews and is supposed to work well for aquarium use. My question is.... Are 8 T5 HO bulbs too much light for the Sofitel and LPS? Is running only 4 at a time (day/night) an option? Any advice would be greatly appreciated.

 

[Phildago]

How many bulbs from front to back? 8?
That doesn't sound insane for t5s only, especially if they're dimmable.

Its more than you need for a bare minimum for sure, but it will also give you good color options, spread and minimal shadowing.

4 blue +
2 coral +
1purple +
1 actinic
Sounds like a t5 dream to me

 

[3rdMoon]

How many bulbs from front to back? 8?
That doesn't sound insane for t5s only, especially if they're dimmable.

Its more than you need for a bare minimum for sure, but it will also give you good color options, spread and minimal shadowing.

4 blue +
2 coral +
1purple +
1 actinic
Sounds like a t5 dream to me

They’re not dimmable. It’s a standard 8 bulb, 2 channel “grow light” I found on Amazon. With the blend of bulbs you mentioned, it that split into day/night? Or running all 8 of those at once?

 

[Flippers4pups]

Use of a Par meter would be beneficial. Most corals do well around the 200-300 par mark. SPS higher around 300-400 mark.

You could raise the fixture up to decrease it's par if needed, since it's non dimmable.

 

[3rdMoon]

Use of a Par meter would be beneficial. Most corals do well around the 200-300 par mark. SPS higher around 300-400 mark.

You could raise the fixture up to decrease it's par if needed, since it's non dimmable.

Sadly, I dont have a Par meter. And.. if I’m looking at buying generic light fixtures on Amazon, it’s fairly obvious I can’t afford one LOL

 

[Crashjack]

How wide is the fixture? I assume your 75 is 18” wide so that fixture might have a lot of spill-over or might have to sit almost on top of the tank.

 

[Flippers4pups]

Sadly, I dont have a Par meter. And.. if I’m looking at buying generic light fixtures on Amazon, it’s fairly obvious I can’t afford one LOL

You could rent one from BRS. Just a option.

 

[3rdMoon]

How wide is the fixture? I assume your 75 is 18” wide so that fixture might have a lot of spill-over or might have to sit almost on top of the tank.

Both the tank and the fixture are 18” wide. Which is part of the problem. I’d kinda planned on DIYing an open topped canopy to direct the light straight into the tank.

 

[3rdMoon]

You could rent one from BRS. Just a option.

That’s true. But I’d have to actually BUY the light before I could even test it with a rented Par meter. That seems slightly counterproductive.

 

[3rdMoon]

Both the tank and the fixture are 18” wide. Which is part of the problem. I’d kinda planned on DIYing an open topped canopy to direct the light straight into the tank.

I’d rather run a 2 channel, 4 bulb TS fixture, which would eliminate a lot of the spacing issue. But finding one that’s reviewed well, that isn’t “dry environment only” isn’t as easy as I thought it would be.

 

[Crashjack]

I’d rather run a 2 channel, 4 bulb TS fixture, which would eliminate a lot of the spacing issue. But finding one that’s reviewed well, that isn’t “dry environment only” isn’t as easy as I thought it would be.

Maybe more money, but the ATI T5 fixtures are pretty nice and well thought of.

 

[3rdMoon]

Maybe more money, but the ATI T5 fixtures are pretty nice and well thought of.

Again, much like the guy who suggested I get a Par meter.... if I’m looking at generic “grow light” fixtures on Amazon, odds are, I can’t afford the ATI T5 fixture. Thanks for the input tho. Happy Thanksgiving

 

[homer1475]

They are on the for sale forum all the time, and for right around what you would buy the crappy "grow lights" on ebay or amazon for. Yes it would be used, but 99% of the time these T5 units are practically brand new as most of them were used a short period because the owner went to LED's.

 

[3rdMoon]

They are on the for sale forum all the time, and for right around what you would buy the crappy "grow lights" on ebay or amazon for. Yes it would be used, but 99% of the time these T5 units are practically brand new as most of them were used a short period because the owner went to LED's.

See now that is the kind of advice I was looking for. Didn’t even realize there was a for sale forum on here. Thank you very much.

 

[Philip Haddock]

On my 120G that has been running for about 16 years I had 8 ATI T5's over it at one point. All I could keep was SPS and Euphilia for the most part, even in the sand bed. The majority of shrooms and zoas would just melt away. Granted they had the correct individual reflectors and run on true T5 ballasts (ran on IceCap 660's that I still have for a long time first). Now I run LED's and 2 T5's and can keep anything. Not sure of the fixture you are looking at but the T5's are really powerful lights is what I'm saying. lol

 

[Jon Mooney]

On my 120G that has been running for about 16 years I had 8 ATI T5's over it at one point. All I could keep was SPS and Euphilia for the most part, even in the sand bed. The majority of shrooms and zoas would just melt away. Granted they had the correct individual reflectors and run on true T5 ballasts (ran on IceCap 660's that I still have for a long time first). Now I run LED's and 2 T5's and can keep anything. Not sure of the fixture you are looking at but the T5's are really powerful lights is what I'm saying. lol

See that type of scenario is exactly what I feared might happen. I don’t wanna damage any livestock due to my own inexperience. My corals shouldn’t have to pay the price for me being a DOPE. I guess I’ll just keep looking. Thanks so much for your anecdotal advice.

 

[DSEKULA]

I'd recommend looking through the build threads at tanks sized similar to yours. See what others are using for the stock you'd like to keep, many of us list our fixtures and lamp choices. If you see someones tank and those things aren't listed you could always post or pm them. My experience is that when such questions are asked most reefers on here are more than happy to share their experiences with others. It's also a great time to watch for sales and used items, many people use blackfriday deals to up grade so you will see their used items get listed too. GL and happy hunting!

 

[Crashjack]

On my 120G that has been running for about 16 years I had 8 ATI T5's over it at one point. All I could keep was SPS and Euphilia for the most part, even in the sand bed. The majority of shrooms and zoas would just melt away. Granted they had the correct individual reflectors and run on true T5 ballasts (ran on IceCap 660's that I still have for a long time first). Now I run LED's and 2 T5's and can keep anything. Not sure of the fixture you are looking at but the T5's are really powerful lights is what I'm saying. lol

A lot depends on your rock work and where you keep stuff. Rock work creates shade and low current areas, which enable you to keep corals that like lower light/flow. T5s are nice in that they don't have hot spots like LEDs (I'm not knocking LEDs and run an LED/T5 hybrid). Buying a used ATI fixture is a great idea. Even if you end up having to replace ballasts, they are not that expensive and easy to replace in an ATI fixture.

 

[DSEKULA]

A lot depends on your rock work and where you keep stuff. Rock work creates shade and low current areas, which enable you to keep corals that like lower light/flow. T5s are nice in that they don't have hot spots like LEDs (I'm not knocking LEDs and run an LED/T5 hybrid). Buying a used ATI fixture is a great idea. Even if you end up having to replace ballasts, they are not that expensive and easy to replace in an ATI fixture.

LEDs won't create hot spots if you spread the diodes evenly (imo correctly) over the tank. A well spaced pattern creates very even light.