Fluval Light Settings for Corals

chicagoreefer1990

New Member
View Badges
Joined
Oct 18, 2025
Messages
11
Reaction score
6
Location
chicago
Rating - 0%
0   0   0
Hi All,

I have the Fluval Marine & Reef Light in the attached picture. My tank is a 75gallon rectangular tank. My light settings are also attached in a picture. Most of my corals look good, including a Kenya tree, GSP, Duncan, mushroom, and a couple others. However, I cannot get zoas to open in my tank for the life of me. I am leaning towards it has something to do with my light settings. Should I ramp them up? Any thoughts are appreciated.

20251116_142937_2EECFF44-E3DD-48CD-8114-3FBAB0504E09.png

20251116_142937_7565743C-3234-4E66-BAB2-90959F0724AC.png
 

lapin

10K Club member
View Badges
Joined
Dec 16, 2017
Messages
11,672
Reaction score
18,286
Location
Austin
Rating - 0%
0   0   0
My suggestion is to ramp up the white light a little as a test to see what difference that makes. Seems a bit low to me.
 

Mr. Mojo Rising

10K Club member
View Badges
Joined
Feb 14, 2021
Messages
13,336
Reaction score
15,812
Location
Toronto
Rating - 0%
0   0   0
Thats a 59 watt light, which IMO is underpowered for your size tank. How many of the bars do you have? Myself I would want about 150-200 watts on that size tank. If you have only one bar then I would crank it to 100
 

ikimonogakari

New Member
View Badges
Joined
Mar 24, 2023
Messages
12
Reaction score
5
Location
US
Rating - 0%
0   0   0
Hi! Did you have any luck? I have a Fluval Evo with the same light only smaller. Sucks because the light wasn't cheap and others recommended it and now people here are saying it's not good for your tank. I have trouble growing coral in the tank too. Did you go with something else? Thanks!
 

twentyleagues

5000 Club Member
View Badges
Joined
Mar 27, 2023
Messages
6,275
Reaction score
7,181
Location
Flint
Rating - 100%
1   0   0
Hi! Did you have any luck? I have a Fluval Evo with the same light only smaller. Sucks because the light wasn't cheap and others recommended it and now people here are saying it's not good for your tank. I have trouble growing coral in the tank too. Did you go with something else? Thanks!
I know this is a bit old of a post and I am not the op, but to try and help answer your question I would say those lights alone are not strong enough. Typical "small" reef capable lights are in the 70-90w range. On a 75g like the op has they would most likely need 3-4 of the "small" reef lights. Going with 3-4 of the fluvals may work as well but the amount spent would not be worth it. I know the packaging says its a reef light but it truly is not. It would be fine for a fowlr tank, or maybe a nps tank since the corals dont need light, maybe very low light softies but even then, I think not.
 

ikimonogakari

New Member
View Badges
Joined
Mar 24, 2023
Messages
12
Reaction score
5
Location
US
Rating - 0%
0   0   0
I know this is a bit old of a post and I am not the op, but to try and help answer your question I would say those lights alone are not strong enough. Typical "small" reef capable lights are in the 70-90w range. On a 75g like the op has they would most likely need 3-4 of the "small" reef lights. Going with 3-4 of the fluvals may work as well but the amount spent would not be worth it. I know the packaging says its a reef light but it truly is not. It would be fine for a fowlr tank, or maybe a nps tank since the corals dont need light, maybe very low light softies but even then, I think not.
Thanks for the reply!! So you think even for my Fluval Evo, the Fluval Sea Marine 22 watt (16-24 in) would be not enough? Anything you would recommend instead with the stock lid? Thanks!
 

twentyleagues

5000 Club Member
View Badges
Joined
Mar 27, 2023
Messages
6,275
Reaction score
7,181
Location
Flint
Rating - 100%
1   0   0
Thanks for the reply!! So you think even for my Fluval Evo, the Fluval Sea Marine 22 watt (16-24 in) would be not enough? Anything you would recommend instead with the stock lid? Thanks!
I am not "up" on the design of that tank, but I see the light is set into the cover. You may want to try looking into an AI Blade in the coral grow color. I dont know if it will fit into the cover but its probably the best option if you want to keep the top. Without the lid you have more options, Kessil, Noopsyche, AI prime, these are a few that I feel are not overpriced too far out of range of a good light for that size tank.
 

hurdler144

New Member
View Badges
Joined
Sep 21, 2025
Messages
1
Reaction score
0
Rating - 0%
0   0   0
Ok I am sorry to disagree with the above people, however, I run that Fluval 4.0 reef on my 55 gallon tank and it is plenty powerful to grow corals. Especially with the collection of corals you are listing. That being said, you will not be able to grow SPS corals with it, but for soft corals and LPS you will be just fine. I run mine with this basic setup:
Blue channels (~60–70%)
White ~20–30%
Red/Cyan ~3–5%
Smooth ramp in/out
9–10 hr photoperiod
and my overall par for this is as following in my tank which is about 18" deep:

  • Top of tank: ~160–180 PAR
  • Mid-column: ~100–140 PAR
  • Sandbed: ~60–100 PAR

With lights, par and spectrum is far more important than Watts, watts is the amount of electricity it takes to run the light, there are different kinds of light that require different amounts of electricity. I have been reef keeping for many years and just recently joined Reef2Reef and this is my first post because I don't want you to get discouraged through negative posts. Ultimately it is up to you to adjust the light according to your needs, with a 75 gallon tank you probably will have slightly lower par and may need to run the channels a bit higher for the same results. I hope this helps.
 

TOP 10 Trending Threads

WHAT AMOUNT OF LIVE ROCK AND SAND SHOULD BE PRIORITIZED FOR OPTIMAL BIODIVERSITY/FILTRATION?

  • 100% live rock + bagged sand

    Votes: 34 27.2%
  • 100% dry rock + 100% live sand

    Votes: 44 35.2%
  • 50/50 live/dry rock, 50/50 live/bagged sand

    Votes: 27 21.6%
  • 75% live rock, 25% live sand

    Votes: 11 8.8%
  • 25% live rock, 75% live sand

    Votes: 9 7.2%
Back
Top