# PAR levels for plants....



## redfishsc (Aug 29, 2010)

Howdy all....

I'm in the midst of setting up a 10g plant tank. I did plant tanks for years, took a break from the hobby, did reef keeping for several years, and recently took the reef down b/c I'm a grad student with no time or money.


So I went back to what I knew was the best 'bang for the buck' in aquarium fun--- small low-tech planted tanks.


Except, I have a nice LED array I had over my reef (couldn't sell it ). 

My array is 24" long and 18" wide, so it's way bigger than a 10g, but I'm growing basil, mint, and cilantro in pots around the tank to catch the unneeded light. 

The array is a blend of 13 Cree XRE royal blues (960mA current) and 13 Cree XPG (1400mA current) with 60 degree optics.

I'm getting a little over 100ppfd on the sandbed and about 200ppfd at the surface of the tank-- using a borrowed Apogee Quantum from a local reef farm.

The overall color is beautiful...except for my driftwood staining the water, hopefully it will stop that after a few w/c's. 

Would you consider this "medium" or "high" light?


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## neumahrs (Jan 12, 2010)

I think you answered the question yourself with the PAR reading. You have medium-high light.


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## Hoppy (Dec 24, 2005)

The high light range I use, which is what Tom Barr recommended to me, is about 80 to 120 micromols of PAR. If you have 100 at the substrate level you have high light. (You can't adjust the light at the surface independent of the substrate.)

If you raise the light to reduce both readings you should enjoy keeping a planted tank a lot more.


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## redfishsc (Aug 29, 2010)

So you're suggesting that I have it a bit lower? Not a problem since the LEDs are all dimmable, assuming the herbs around it don't mind the light being a bit dimmer. 

I do plan on using the DIY CO2 plan I used years ago (sugar/yeast homebrew).

I'm picking up a used Rena XP3 canister filter today ($50, hard to beat that). If I can keep the flow down to a sane level, I'll use that as the filter and also as a CO2 reactor.


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## Hoppy (Dec 24, 2005)

You can recognize planted tank keepers who use medium to low light intensity from those who have high light. Those with the higher light tend to have gray hair, and fewer smiles.:icon_eek: So, yes I recommend dropping the substrate light level to around 60 or so micromols of PAR.


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## redfishsc (Aug 29, 2010)

Thanks Hoppy, I will do that. Fortunately that's easy enough . I love these LEDs.


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