Guidance on determining and adjusting light intensity

[Pepere]

If PAR meters were not so expensive, it would be nice to have one.. You could see if the carpeting plants were getting the recommended PAR to form that lush thick carpet and if your Red plants were getting enough to be their most brilliant..

But, absent a Par meter, is there any guidance on how to determine how bright tohave your light?

Go with the assumption brighter is better until it isnt, and gradually bump it up until you see problems and then back it off a bit… and maybe try again after a week or two as plant adjusts???

Any tips or guidance appreciated…

 

[Art]

Hi,

So PAR doesn't equal brightness. What light are you using? Perhaps we can assist with tuning it for you.

One "hack" I've recently done as I try to get my tank back into shape is use the Photone app for iPhone. I heard about it from @Dennis Wong and it gives you a pretty good approximation of PAR levels without a PAR meter. Perhaps try that?

 

[Pepere]

So PAR doesn't equal brightness. What light are you using?

Well perhaps my terminology is off, but I suspect PAR will increase if I increase the power the light is producing…. And it surely will look brighter to my eye as well…

2 ChihirosWRGB2 pros. CO 2 injection to a fairly high level.





I have read that the iphone apps can be off as much as 30% on PAR.

Also, part of me is rather reluctant to submerge my Iphone intoa tank of water and rely on water integrity of a ziploc plastic bag.

I think it would be cheaper to invest in a PAR meter than replace a wet I phone…

 

[Pepere]

Current settings
Red 90
Green 70
Blue 105
White 0

Above photo is with ipad with exposure knocked down so background looks black.




This photo is with auto exposure.

 

[FrankZ]

SCAPECRUNCH test on the photon app

 

[FrankZ]

I hope that link works. @Yugang posted the question and @fablau compared the photon app to his PAR meter. Readings matched up fairly well.

 

[Art]

I have read that the iphone apps can be off as much as 30% on PAR.

Also, part of me is rather reluctant to submerge my Iphone intoa tank of water and rely on water integrity of a ziploc plastic bag.

I think it would be cheaper to invest in a PAR meter than replace a wet I phone…

I think @Dennis Wong's testing showed that for general PAR readings, it was fine. For precision (25 verses 28 PAR), you need a meter. However, for our purposes, you just need to get it to a reasonable range and the app should be find.

And, yes, I would not submerge your phone. My thought is to use it when you do a large water change so that you don't have to submerge it.

 

[Pepere]

Ok. I read the thread in question, I downloaded the app to the phone…. I am playing around with it…

But more to the point… how do you, and everybody else here, personally settle on a light intensity on your tanks?

How do you decide you want to nudge up the settings or drop them down a bit?

What are you looking for with the plants?

I am fairly happy with my color rendering setpoints,

 

[RickyV]

But more to the point… how do you, and everybody else here, personally settle on a light intensity on your tanks?

Having experience wirh deep tanks (4ft and 2.5ft) I've learned plants can get by with a lot less light than we think we need. I grew a lush dwarf hair grass carpet 4ft deep in a shaded area with Fluval Plant 3.0 lights.

This 2.5ft deep tank was grown with 3 WRGB II pros at 50% power.

So knowing that I start my tanks on the lower end of lighting intensity. I try to find a brightness that's appealing to my eyes with lower intensity. Often times I'll find that the lower intensity I started with gets me the results I want and I have no reason to keep pushing the light. But now being more confident in my ability to grow plants with minimal algae I push the lights a little more (keep in mind I have deep tanks).

 

[Pepere]

But now being more confident in my ability to grow plants with minimal algae I push the lights a little more

I have had success keeping Algae at bay for the past year. Even started a non co2 fish bowl running on air driven box filter and modified UGF that is free of visible algae.

But I keep looking over my back, expecting it to over run my tank overnight some day…. A recurring fear…. Hesitant to alter things too much and get knocked off the knife edge of balance…. Just like the sports fan who always sits in the same chair wearing his lucky shirt and same brand of beer to make sure his team wins…..