LED Lighting for 20G long - Page 2 - Lighting - Aquatic Plant Central

Go Back   Aquatic Plant Central > Special Interest Forums > Lighting

Lighting Science of Aquatic Lighting - Aquarium lighting is essential for healthy aquatic plants. Discuss proper aquatic lighting for your plants and fish here.

LinkBack Thread Tools Display Modes
Old 07-03-2018, 04:16 PM   #11 (permalink)
Join Date: Apr 2006
Posts: 2,556
iTrader Ratings: 0
dwalstad is a regular member
Default Re: LED Lighting for 20G long

Originally Posted by hoppycalif View Post
Most plants start their life at the substrate, and it is during that early growth period that plants either grow well or don't grow well. Based on that it is much better to measure light intensity at the substrate, not at the water-air interface. If you have a tall tank, like a 20 high tank, a high PAR reading at the top of the water column, with the light sitting on top of the tank, doesn't mean you have adequate light at the substrate. And, a high PAR reading at the top of the water column can mean much too much light at the substrate, if you have a low tank, like a 20 long tank. I suspect that some day someone will come up with a better way to use a PAR meter, when choosing a light fixture, but for now I strongly suggest always going by the PAR reading at the substrate.
Yes, but you should be able to calculate PAR at the substrate based on surface measurements. As light passes through a certain distance of water, it loses its intensity in a straightforward way.

I have established tanks so overhead light is absorbed by floating plants and plants already in the tank. So substrate measurements are misleading, especially since I now have bare glass bottoms with plants in pots.

That said, I measured about 5-20 PAR at the glass bottom of my 20 gal Long (12" high).

Lighting is complicated. We could split hairs all day, but I hope the information that I have provided will be useful.
dwalstad is offline   Reply With Quote

Advertisement [Remove Advertisement]
Old 07-03-2018, 05:23 PM   #12 (permalink)
Senior Member
Maryland Guppy's Avatar
Join Date: Mar 2015
Posts: 348
iTrader Ratings: 2
iTrader Positive Rating: 100%
Maryland Guppy is a regular member
Default Re: LED Lighting for 20G long

@Hoppy is right on PAR!

Measure @ the substrate.

Floating plants typically get full sun, doesn't matter much to them.

Shading can be the downfall of many plants.
Maryland Guppy is offline   Reply With Quote
Old 01-15-2021, 08:49 AM   #13 (permalink)
Junior Member
Join Date: Jan 2021
Posts: 1
iTrader Ratings: 0
JudeMosler is a regular member
Default Re: LED Lighting for 20G long

Hi... In the event that cash is the restricting element, at that point I would genuinely consider a modest T5HO installation first off and keep on seeing what LED you may need. Driven looks better, T5 is simpler to arrangement and develop corals. Driven works much better with more pucks and the splendor diminished, instead of only a couple pucks turned far up. Hotspots can be a genuine issue when you need more spread.
JudeMosler is offline   Reply With Quote

Aquatic Plant Central > Special Interest Forums > Lighting > LED Lighting for 20G long

Thread Tools
Display Modes

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 08:03 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

Search Engine Friendly URLs by vBSEO 3.6.1