Reef Central Online Community
Tampa Bay Saltwater

Home Forum Here you can view your subscribed threads, work with private messages and edit your profile and preferences View New Posts View Today's Posts

Find other members Frequently Asked Questions Search Reefkeeping ...an online magazine for marine aquarists Support our sponsors and mention Reef Central

Go Back   Reef Central Online Community > General Interest Forums > Lighting, Filtration & Other Equipment
Register Blogs FAQ Calendar Mark Forums Read

Notices

User Tag List

Reply
Thread Tools
Old 06/27/2020, 09:16 AM   #1
illumnae
Registered Member
 
Join Date: Sep 2012
Location: Singapore
Posts: 321
Lighting for very tall tank

Does anyone have recommendation for lights for an extremely tall tank, about 40-48 inches of water height? I just need to be able to see the fish in a fowlr setup, no need to keep any corals alive.


illumnae is offline   Reply With Quote
Old 06/27/2020, 09:19 AM   #2
Sk8r
RC Mod
 
Sk8r's Avatar
 
Join Date: Feb 2006
Location: Spokane WA
Posts: 33,821
Blog Entries: 55
I have a 36 deep, and Ecolabs Radion unit does it, but they are, however, coral gear, and are spendy.


__________________
Sk8r

Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low.

Current Tank Info: 105g AquaVim wedge, chromis, royal gramma basslet, tailspot blenny, ocellaris clown, yellow watchman, chestnut turbo snails, bristleworms, couple of hermits.
Sk8r is offline   Reply With Quote
Old 06/27/2020, 10:28 AM   #3
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
Metal halide pendant.

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Old 06/27/2020, 10:30 AM   #4
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
I personally think fish look really good under ushio 10k MH.

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Old 06/27/2020, 10:32 AM   #5
kharmaguru
Registered Member
 
kharmaguru's Avatar
 
Join Date: Jul 2010
Location: Oshawa, ON
Posts: 120
Agree with halide pendant. Other narrow beam spotlights, par38 etc could work.


__________________
Master Algae Grower

Current Tank Info: 20 gallon mixed reef, mangroves, algae scrubber, DIY LEDs
kharmaguru is offline   Reply With Quote
Old 06/27/2020, 09:01 PM   #6
illumnae
Registered Member
 
Join Date: Sep 2012
Location: Singapore
Posts: 321
I did consider t5 and mh before but prefer led for controllability.

Good to hear that radio's work at 36". How dim is it at 36"? Light dropoff is exponential in water right? Do you think it would be strong enough for another 12" of water height? Given that height penetration is about the power of each individual led and not the spread, do you think even an AI prime would do the trick given it uses similar wattage led diodes but just with less of them?


illumnae is offline   Reply With Quote
Old 06/28/2020, 11:42 PM   #7
dzfish17
Registered Member
 
dzfish17's Avatar
 
Join Date: Feb 2010
Location: Fresno,Ca.
Posts: 2,539
I'm in the same situation (46" height) and am looking at the kessil 360ne as an option


__________________
600g (96x36x46) FOWLR
dzfish17 is offline   Reply With Quote
Old 07/01/2020, 12:18 PM   #8
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,746
Quote:
Originally Posted by illumnae View Post
Light dropoff is exponential in water right? Do you think it would be strong enough for another 12" of water height? Given that height penetration is about the power of each individual led and not the spread, do you think even an AI prime would do the trick given it uses similar wattage led diodes but just with less of them?
Depends on how you look at it..
A "panel" is not a point light source nor is it shining into "free space"..
It can be quite linear in certain ranges..
Examples (planted tank bulbs)




Last edited by oreo57; 07/01/2020 at 12:26 PM.
oreo57 is offline   Reply With Quote
Old 07/01/2020, 05:45 PM   #9
illumnae
Registered Member
 
Join Date: Sep 2012
Location: Singapore
Posts: 321
Sorry I'm not very good at math, but doesn't the curve show it's exponential? Linear dropoff would be a straight line?


illumnae is offline   Reply With Quote
Old 07/01/2020, 07:53 PM   #10
cody6766
Super Best Friends!
 
cody6766's Avatar
 
Join Date: Jan 2008
Location: OKC, OK
Posts: 3,628
Extreme depth like that will want an over abundance of LEDs or a pretty dense MH array. There's nothing that says that you can't combine the two, but digging down 4' takes some intensity. LEDs are great for spot intensity or medium spread. MH is great for spot intensity and pretty good for spread. I don't have any experience deeper than 24", but I'd imagine you're going to need a lot of energy to get 4' down, no matter what lighting type you use. 400w metal halide with LED or T5 color supplementation would be my best guess for the best solution. The 400w MH could be replaced with LEDs, but your going to need at least 2x the fixtures that you'd need for a 2' deep tank...probably.

I've never tested this, but I've had a a 2' deep tank, MH, T5s and LEDs on it. Getting double the penetration would have been bat excrement crazy compared to what I had over my tank.


__________________
"The moral is the chosen, not the forced; the understood, not the obeyed. The moral is the rational, and reason accepts no commandments." - John Galt

Current Tank Info: Cadlights 60G Arisan II mixed reef with 2x MP40s and 24" ATI
cody6766 is online now   Reply With Quote
Old 07/02/2020, 12:44 AM   #11
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,746
Quote:
Originally Posted by illumnae View Post
Sorry I'm not very good at math, but doesn't the curve show it's exponential? Linear dropoff would be a straight line?
Yes but I stated in ranges..
Quote:
The intensity of light radiating from a point source is inversely proportional to the square of the distance from the source; so, an object (of the same size) twice as far away receives only one-quarter the light in the same time period.
so let's take the ATI at 15 and 30 inches
138 @ 15" so should be 34.5 PAR at 30"
Chart says 60.....almost 2x the expected.



Also like this (see green lines on brown curve) Like the slope of the curve at different ranges:



See tanks don't exactly let down-welling light out that easy.. unlike free space so it throws off the calculations.



Take reading at 12" and divide by 4.. see how well it matches par at 24"

Maybe I'm looking at it the wrong way but point is we have tanks that behave more in a linear fashion than log BUT each has errors....
If you use 6" and 12" the PAR is more 1/2 than 1/4..

1/4 of 45 = 11.25 Measured.. 21 ect. ect..
go bigger..
6" 12" 24"
45, 11.25, 2.81
real;
45, 21, 7
1/2
45 22.5, 11.25

suppose it's sort of an odd way to look at it..
2x the distance 1/2 the PAR..... Linear probably isn't THE correct term..just smoother than expected.



Last edited by oreo57; 07/02/2020 at 01:06 AM.
oreo57 is offline   Reply With Quote
Old 07/03/2020, 08:20 PM   #12
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
Inverse square law?

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Old 07/03/2020, 10:48 PM   #13
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,746
Quote:
Originally Posted by doonan75 View Post
Inverse square law?

Sent from my Moto G (4) using Tapatalk
Quote:
For example, the intensity of radiation from the Sun is 9126 watts per square meter at the distance of Mercury (0.387 AU); but only 1367 watts per square meter at the distance of Earth (1 AU)—an approximate threefold increase in distance results in an approximate ninefold decrease in intensity of radiation.
3 squared = 9..inverse 1/9

2x distance = 1/distance squared =1/4

Instead of losing twice the PPFD at twice the distance you lose 4x the "PAR" (PPFD)


oreo57 is offline   Reply With Quote
Old 07/03/2020, 11:34 PM   #14
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
Lol I thought what you were explaining sounded familiar. It's a shame that most people don't know what that is. It's literally basic high school science.

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Old 07/03/2020, 11:38 PM   #15
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
Also I just went to Sea world and most of their deep tanks use MH as the primary lighting. The aquarium exhibit at the Manta coaster is amazing

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Old 07/04/2020, 08:19 AM   #16
Vinny Kreyling
Registered Member
 
Vinny Kreyling's Avatar
 
Join Date: Nov 2002
Location: Miller Place, NY
Posts: 6,547
Not being "smart" in this technology means take with a grain of salt --
I have seen a tank lit by LED'S from 15 feet above here on RC by Timfish I believe.
He used 15 degree optics. Would this approach of running a narrow beam do the job?


__________________
250 gallon mixed reef, 2 Reefbreeder's Photon V 2, RD 3 Speedy 80 Watt, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.
Vinny Kreyling is offline   Reply With Quote
Old Today, 08:53 AM   #17
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,746
Quote:
Originally Posted by Vinny Kreyling View Post
Not being "smart" in this technology means take with a grain of salt --
I have seen a tank lit by LED'S from 15 feet above here on RC by Timfish I believe.
He used 15 degree optics. Would this approach of running a narrow beam do the job?
Yes...
https://store.marinebeam.com/beam-angle-calculator-1/

15 degrees at 15 ft gives a spot size of 3.95ft..


oreo57 is offline   Reply With Quote
Old Today, 05:19 PM   #18
doonan75
Registered Member
 
Join Date: Jun 2004
Location: North Palm Beach FL
Posts: 180
Quote:
Originally Posted by Vinny Kreyling View Post
Not being "smart" in this technology means take with a grain of salt --
I have seen a tank lit by LED'S from 15 feet above here on RC by Timfish I believe.
He used 15 degree optics. Would this approach of running a narrow beam do the job?
I would think so since coral is not a concern, but I still like halides. I'm lucky to live near the gulf stream so our water is very clear and from my eye perception nothing beats a 10-20k MH for true representation.

Sent from my Moto G (4) using Tapatalk


doonan75 is online now   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -6. The time now is 09:56 PM.


TapaTalk Enabled

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2020 Axivo Inc.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef CentralTM Reef Central, LLC. Copyright 1999-2014
User Alert System provided by Advanced User Tagging v3.3.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.