# Par Levels at the substrate...



## Mathman (Apr 5, 2009)

Hello folks,

What par reading at the substrate right below the light is currently considered "high" "medium" "low" light in a planted tank?

What readings do you have and what plants are you able to grow without any issues?

Thanks.



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## Esteban Colberto (Mar 7, 2017)

0-30 micromols of PAR - Low
30 - 50 micromols of PAR - Medium
50+ micromols of PAR - High

Taken from this Planted Tank thread.

P.S. - Oh Arsenal we love you!


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## Mathman (Apr 5, 2009)

Esteban Colberto said:


> 0-30 micromols of PAR - Low
> 30 - 50 micromols of PAR - Medium
> 50+ micromols of PAR - High
> 
> ...




Thanks for the quick reply. I also have seen that thread before, I wonder if those levels are still the same seeing that the thread is back from 2012.

•••Barca •••


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## jeffkrol (Jun 5, 2013)

In taxonomy ther are "lumpers" and "splitters".. 
I'm more of a splitter by nature..
high/med/low would have 2 def depending on high tech or low tech..
Can be further split to high tech:high demand/low demand plants.. ect.
May be going a bit too far though.. but you can see where this is going..

50PAR may be medium for high tech/high demand plants..


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## Esteban Colberto (Mar 7, 2017)

jeffkrol said:


> In taxonomy ther are "lumpers" and "splitters"..
> I'm more of a splitter by nature..
> high/med/low would have 2 def depending on high tech or low tech..
> Can be further split to high tech:high demand/low demand plants.. ect.
> ...


It's just like any other scale, you can set it to whatever you want. I don't think the scale in the referred post is influenced by a tank being high or low tech but maybe I didn't read it well enough. It's a lot easier for me to think that a high tech tank needs high light levels (based on the described, general scale) vs changing the scale itself.


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## jeffkrol (Jun 5, 2013)

> The concept of good/average/poor PAR values only has meaning in relation to the level of CO2 being injected. If CO2 is being injected that the injection efficiency and the gas distribution will be factors for good/average/poor PAR.
> To simplify, and to have a more meaningful use of the PAR values, consider that in general, PAR measured at the substrate level will determine whether the lighting is low, medium or high. That is what wazuck was showing in his chart and I think that is what you should focus on. Once you know whether your lighting is low/medium/high then,as wazuck mentions, you can determine what steps are necessary to have good/average/poor.
> 
> If PAR at the substrate level is approximately 50 micromoles or less, this is generally considered low light.
> ...


https://www.ukaps.org/forum/threads/par-readings-what-are-good-readings.26134/
I suppose a chart for CO2/Fert tanks..

Addendum.. Just get a lot of watts and a dimmer.. Never have to worry again.. 



> Most Dutch tanks will do fine with 70 PAR at substrate. Some red Ludwigia will be happier at 100 PAR, but even they will be OK at 70. They will look better at 100.


https://barrreport.com/threads/par-level-for-dutch-tank.13839/

Like I said ..depends on plants ect...




> Low light might be 25-40, 40-60 for med light and 60-80 for high/med, 80-120 micromol for high light.
> Regards,
> Tom Barr


https://barrreport.com/threads/massaged-par-data-for-t5ho-lights.5865/


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## OreoP (Aug 12, 2016)

Anyone know where I can rent a par meter. Got into the hobby too late to buy a "Hoppy" meter. Cannot justify spending ≥$200!!!


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## Dman911 (Nov 24, 2016)

OreoP said:


> Anyone know where I can rent a par meter. Got into the hobby too late to buy a "Hoppy" meter. Cannot justify spending ≥$200!!!


Local aquarium clubs usually have one they are willing to lend out to members. Or some of the members may have and be willing to go to your house and test it.

Dan


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## jeffkrol (Jun 5, 2013)

OreoP said:


> Anyone know where I can rent a par meter. Got into the hobby too late to buy a "Hoppy" meter. Cannot justify spending ≥$200!!!


buy a $20 LUX meter and measure it dry..few are waterproof esp. for 20.
divide reading by 67-ish.. Ballpark figure.


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## clownplanted (Mar 3, 2017)

The way I see it since light is such an important part of planted tanks I figured that the par meter is a VERY good investment. They really are about the same price as a good filter and figure since light is so important I got the Seneye Reef Monitor that has a par meter. One of if not the best investment for my planted tanks. https://www.amazon.com/SENEYE-Reef-...498751675&sr=8-1&keywords=seneye+reef+monitor

I can now take readings ANYTIME I want in ANY of my tanks. For example I knew I had too much light in my 20L tank that has just 15ppm co2 but how much was too much? I knew I had to dim it and got a dimmer for the light but how much do I dim it? I knew the exact amount of par I wanted at substrate and was able to do that with this thing. Pretty cool.


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## Seattle_Aquarist (Jun 15, 2008)

Hi OreoP,

Hoppycalf offers a PAR meter for "rent" (which covers his cost of outgoing postage and insurance). He can be found on this forum.


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