Am I providing enough T5 light for my acros?

[Giek]

I'll discuss briefly my lighting and setup, I'm more than happy to take any advice by someone more experienced than me ..

My tank is 32"x14"x16"h, ATI 4x39w 36" T5 fixture. I'm supplementing with additional total 30w RB led strips for a visual pop, and fixture + leds are 6" off the water. I'm running a mix of Giesemann and ATI, corresponding to 2B+, 2C+ bulbs.
Photoperiod: 12 hours Leds full power and 9 hours all T5s full power.
As in the title, Acros are the goal, my rockscape occupies the lower half of the tank. I haven't the access to a PAR meter, and I'm not able to judge the "brightness" by the eye.

In your experience, not considering key factors like flow and nutrient management (or supposing them to be at the best possible) and considering the light aspect only, is my setup enough, or best, for acros? May, or should, I increase light? I could only do that by adding more led power. Is it already enough or can I push more? I'm quite new to sticks and reefing in general, so I can't really judge based on growth or overall health, not having any database info to compare with.
I've had some frags for 3/4 months, and others for a few weeks. They're doing ok, slightly encrusting a few millimeters and/or slowly growing from the tips.
What's your opinion about my lighting
setup? Cheers from Italy

Photo has been modified, so it's not indicative of the actual brightness in the tank. That's just for a reference of the coral position in the tank

 

[Twocorns]

Best thing to do is get a par meter and see exactly how much light you're already providing your tank, and go from there.

 

[rtparty]

A 4 bulb ATI fixture over that tank is plenty for anything you want. I ran a 4x24w ATI Sunpower over a 40B for a couple years and grew anything I wanted. Old pic from around 2010 when I had this setup

 

[Kodski]

You cannot judge how strong a light is with the human eye. Its not possible even for the pro's who've been in the hobby for 20 years. You NEED a par meter to tell how strong your light is. Luckily for you, there is lots of par data on the 4 bulb T5 fixtures out there, so you could probably skip the par meter. Check out this old thread, it has par measurements for a 4 bulb ATI Sunpower fixture. Length of the fixture makes a negligible difference.

T5 reflectors -- 4 bulb ATI vs Aquatic Life hybrid PAR

This is pure visual representation of data taken from BRS. I haven't seen this comparison. The numbers made me wonder... If we took the higher grade ATI reflectors and put them in the AquaticLife fixture would PAR be identical? I can't test this, but the difference is notable between the two...

www.reef2reef.com

As for the ReefBreeders LED bar, I actually have one. When I tested mine I was seeing an increase of about 80-100 par. Of course exact numbers would be different for different blends of LED diodes. My measurements were for the Blue/UV Hybrid bar.

In short, I'd say safely that without a par meter you are right where you should be par wise for SPS. It looks like your tank isn't super super old yet. Just give it time, if you're seeing encrusting already that's a great sign. If you continue to question your growth rate, I'd look towards other aspects of your care.

Edit: I should mention that your tank looks great! Personally, I'd just keep doing what you're doing. Too many changes to try and chase numbers or growth often times does more harm than good.

 

[fishface NJ]

The ATI T5 light is plenty. How high is the T5 from the water?

 

[spsick]

Similar to @rtparty I had a 40bdr with 6x24 running shorter photoperiod that you over a 40 breeder that grew all these from tiny frags. OP- you have plenty of light.

 

[Giek]

Thanks to everyone responding. Very helpful advice from y'all.

I'll consider getting my hands on a par meter in future, at the moment I'll just let things the way they are.
Just to clarify, "RB" in my post stands for Royal Blue (LEDs). I've added only them (with a bit of DIY) to get a nice pop in colours, and to have a great view of fluorescent corals before lights go down.

Really appreciate the visual testimony from your previous tanks.

Yeah, the tank has been set up for less than a year, but heavy changes have been made just a few months ago, both in tech and methods, plus basically restarting with several new frags. I'll just let things settle for a while to see how the system adapts to my routine.
If you're interested in updates, follow my tank thread!

Again, thanks everyone

 

[bobnicaragua]

Thanks to everyone responding. Very helpful advice from y'all.

I'll consider getting my hands on a par meter in future, at the moment I'll just let things the way they are.
Just to clarify, "RB" in my post stands for Royal Blue (LEDs). I've added only them (with a bit of DIY) to get a nice pop in colours, and to have a great view of fluorescent corals before lights go down.

Really appreciate the visual testimony from your previous tanks.

Yeah, the tank has been set up for less than a year, but heavy changes have been made just a few months ago, both in tech and methods, plus basically restarting with several new frags. I'll just let things settle for a while to see how the system adapts to my routine.
If you're interested in updates, follow my tank thread!

Again, thanks everyone

Your corals look good. The tank is only 16” deep and you’re running 4 T5 with 2 LED strips. You don’t need a par meter.

You did a good job, acros thrive under T5.

 

[Miami Reef]

You don’t really need a par meter for T5. It’s really difficult to burn acropora with normal T5 bulbs and fixtures. They should do well.

Of course, you can always rent a par meter if you’d like, but I think the whole purpose of T5 is that it’s “plug-and-play.”

 

[sjfishguy]

You don’t need a par meter, that ATI fixture is PLENTY of light for any acro in that tank. You don’t even need those LEDs. I have a 48” 8 bulb ATI powermodule over my 120 and I think it’s too much light. You’re good