The Planted Tank Forum

The Planted Tank Forum (
-   Low Tech Forum (
-   -   Question about PAR values (

farnaby 03-21-2013 09:36 PM

Question about PAR values
I recently purchased a 29 gallon aquarium and a 30" fugeray. So I'm sitting here looking over the Finnex provided PAR values and I'm wondering this: Let's say I have a 8" plant that requires medium - high light, do I need to worry about the PAR values at the bottom of the plant or will the amount of light at the top be sufficient?

Thanks in advance!

mitchfish9 03-21-2013 10:06 PM

That medium-high light should be extended to the substrate for that plant to really grow and thrive. So i don't think it will be enough. But what is the plant?

farnaby 03-21-2013 10:14 PM

The plant in the above scenario was hypothetical, but I do have these guys lined up:
L. repens
H. augustifolia
Cabomba caroliniana
Broadleaf water sprite
Azolla caroliniana
Salvinia minima
Java moss
Java ferns

mitchfish9 03-22-2013 01:21 AM

Your absolutely fine with about the 25 PAR you currently have with all those plants. But I would always think of PAR at the substrate, because the last thing you want are plants that have no leaves at the bottom, because that just doesnt look very good. With the lighting you have you are in pretty good shape in terms of plant selection

farnaby 03-22-2013 02:44 AM

Awesome, thanks for putting my mind at easy!

Hoppy 03-22-2013 03:12 AM

You can look at PAR as a local measurement at each plant, and at various areas of that plant. Or, you can just use PAR as a general way to determine if you have the light level you desire, measuring it only at the substrate. I like the latter, because it gives me one number I can use to define how "good" that light setup is. It is very hard to try to set the PAR for multiple points in the tank at the same time, so why even try. When we say 25-35 is low light for PAR at the substrate that doesn't mean the whole plant sees that light level at all parts of the tank. Every part above the substrate sees more light than that, but the tank is still a low light tank. Similarly, if the PAR at the substrate is 80, that isn't extremely high light, even though all areas above the substrate see much more than 80 PAR. I hope that isn't confusing.

farnaby 03-22-2013 05:03 AM

It makes total sense Hoppy and I thank you for taking the time to explain it (and thanks to MitchFish as well).

I just wanted to clarify things up a bit so that I can make sure that my plant stock is appropriate for my lighting levels.

I start planting on Saturday and I'm extremely excited!

All times are GMT. The time now is 01:30 AM.

Powered by vBulletin®
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.