# Lighting - Photoperiod/Rest



## Vandal Gardener (14 Nov 2017)

Apologies I have a memory that sticks with things that conveniently gets on with how I think!

I remember reading somewhere that periods of 4 hours were the cycle that need to be hit before it meant anything of substance to the plant, otherwise sort of like storms or moonlight, i don't know my knowledge really is suspect and woolly but the 4 hours thing always struck, so the notion of a break always confused me cause is it the light that needs to be 4  hours?  and the hour break just drops intensity so is an opportunity for co2 to replenish, because it's below 4 hours doesn't have an effect lighting.  Or is this 4  hours bunkum(sp)?  

Seriously does this even sound familiar to any of you?

I do wonder how gullible I am at times


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## Edvet (15 Nov 2017)

In hich tech high light the plants wil "eat" it's fill in about for hours. The break is sometimes used in low tech tanks, but is mostly deemed not functional nowadays.


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## Vandal Gardener (15 Nov 2017)

Cheers for the response Edvet,

Turns out with a clearer head I found it, I thought it was one of the old manufacturers guides like Dennerle or even Dupla but it was a piece written by the forums very own Mr  F circa 2005 which brought back memories of old forums 
Reading back today reminds me why I should stay away from the keyboard when foggy of head 

All the best
*
(Pasted from fishforums.net http://www.fishforums.net/threads/basic-guide-to-lighting.96754/ )
*
*Lighting Duration (Photoperiod)* 

In nature plants receive around 12 hours of sunlight per day. This can simulated by having the tank illuminated for a similar period. However, some plants will thrive with a reduced photoperiod and this brings the benefits of less possible algae growth but bear in mind that plants generally do not recognise light periods of less than 4 hours. For added benefit to fish and plants the lighting can be switched on and off in stages. This is possible with multiple tubes/light controllers and two or more timers. An example is having one tube on for an hour followed by all the tubes. At the end of the photoperiod the lighting can be dimmed in a similar fashion. This is particularly less stressful for the fish as they are not subject to sudden lighting extremes.

*Photoperiod Gaps and Timers* 

A relatively new concept in lighting is to have a gap or “siesta” in the photoperiod. Plants can apparently adapt to a small dark period whereas algae is not so adaptable. Recommended siesta periods can be from 1 hour to 4 hours with a minimum of 4 hours of lighting either side of the siesta. This is a popular method of limiting algae growth and personally of have had great success with it and still run my lighting with a 2 hour siesta, with 5 hours of lighting either side (5 on, 2 off, 5 on). I can assume that the plants recognise that there is 12 hours of light even though the tank actually illuminated for 10 hours.

Timers are a very effective and convenient method of controlling photoperiods. One can set the timer to switch off at a time most suitable to the viewer. Personally my lights switch off just before my “bed time”.

ETA - the info I referred to


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## ceg4048 (15 Nov 2017)

Vandal Gardener said:


> *Photoperiod Gaps and Timers*
> 
> A relatively new concept in lighting is to have a gap or “siesta” in the photoperiod. Plants can apparently adapt to a small dark period whereas algae is not so adaptable. Recommended siesta periods can be from 1 hour to 4 hours with a minimum of 4 hours of lighting either side of the siesta. This is a popular method of limiting algae growth and personally of have had great success with it and still run my lighting with a 2 hour siesta, with 5 hours of lighting either side (5 on, 2 off, 5 on). I can assume that the plants recognise that there is 12 hours of light even though the tank actually illuminated for 10 hours.
> 
> ...


Hello,
      These statements have little validity because the opposite is true. Plants have very complex mechanisms and because of the complexity they do NOT readily adapt to instability. Algae, on the other hand have very simple systems, are quick and agile and adapt easily to instability or extreme conditions.

Therefore, the so-called "siesta" does nothing to improve the ability of plants to resist algal attacks.

There is no data that verifies the authors claims but there is plenty of evidence to the contrary.

You can sometimes see the behavior in stem plants under high lighting/CO2. In the early part of the photoperiod the leaves are wide open to collect light:



 

Later on in the afternoon, the stems, having had their fill, close up shop:
So if anything, when the lights are bright, they plants will sometimes be seen to enter a protective mode:


 

Light intensity is a much more important issue than duration. Under normal conditions, plants are able to regulate the input energy. So just because light is available for 12 hours, it does not necessarily mean that they are using the light for that amount of time. More often than not, the plant actually has to defend itself against overzealous lighting rather than to "soak it up" for 12 hours.

I do think it is a good thing however, to regulate the intensity so that the lights are dimmed in the beginning and dimmed near the end of the photperiod to accommodate their usage pattern. There is no point in shutting off the light in the middle of the day. Lack of light shuts down their systems and when the lights go on again it takes a lot of time for those systems to return to efficiency. Alga are always efficient under just about every condition, so siesta benefits algae more so than plants.

Better value is added by controlling the intensity and by paying attention to CO2 techniques.

Cheers,


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## Rodgie (15 Nov 2017)

Hi sir Ceg,

If the tank is on Co2 at all no Excel even and it's planned to be a low tech tank. With an LED light that is about 821 lumen and 11 inches above the substrate. How long do you think would be the best photoperiod for low tech slow growing plants? 

Thank you,
Rodgie


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## Vandal Gardener (15 Nov 2017)

Thank you guys for taking time to explain, I've explained to Edvet before that I keep reading and attempting to store the info so that one day it'll all just click.  To be honest it does after a while but that Eureka moment for me is more often a fist palm.

I think the thing I keep forgetting when reading all the threads here is context of how the tank operates and what actually constitutes a hi or low tech.  Is it simply pressurized injected co2 or any kind of co2 (DIY) with high lighting? 

Regardless I'm slavering now, but am really chuffed, especially with the Aromatica porn (honoured  )


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## ceg4048 (15 Nov 2017)

Rodgie said:


> Hi sir Ceg,
> 
> If the tank is on Co2 at all no Excel even and it's planned to be a low tech tank. With an LED light that is about 821 lumen and 11 inches above the substrate. How long do you think would be the best photoperiod for low tech slow growing plants?
> 
> ...


Hi Rodgie,
               Well, Lumens is not a good measurement for plants. PAR is the most appropriate measurements. In order to convert the lumen output of a light source you need know what the conversion factor for that type of light is. If you check the Apogee website https://www.apogeeinstruments.com/conversion-ppf-to-lux/ you'll see that they took measurements for typical types of bulbs and plotted their Lux output against their PAR measurements and determined the factors for those bulbs. Unfortunately, they have not done so for standard LEDs. You also need to know the total surface area at the waters surface (length x width) in order to convert lumens to Lux.
Lux = (total lumens) / (total area in square metres)
PAR at the surface = Lux x conversion factor

So for example, if you were using a flourescent lamp (and it's not clear whether this is a T5) and lets say your tank was 50cm x 20cm (0.1 sq meter)

Lux = 821 / 0.1 = 8210

PAR = 8210 x .0135 = 111 micromoles

That would only tell you what the PAR is at the bulb  and more or less at the waters surface. It does not tell you what is happening at the substrate level.
In a small tank, that is a lot of light. In a taller tank then it would not be as bad.
Again, we do not have a conversion factor for LED, bit if that lamp is anywhere close to what a T5 would output then this is a lot for a small non CO2 tank.

I always suggest caution with LEDs because they are developed for Klingons who worship at the Temple of Megawatt.
If you have a controller I suggest dimming the lights down to 30%-40% at least in the beginning. If no dimmer is available then go for floating plants or a darkend plexigalss cover to reduce the lighting.

A lot of assumptions on my part anyway. I could be way off in either direction...

Cheers,


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## Rodgie (15 Nov 2017)

https://www.amazon.com/gp/aw/d/B008...etailBullets_secondary_view_div_1510788321252


Haha that's more complicated than I thought. I'll try to do the equation when I get home. Right now, on top is the link of the tank I'm going to purchase.

It doesn't say anything about PAR. 

Tank dimension is:
17.2x10.6x6.3

A lot of people say it's bright, (but I do t wanna depend on these reviews) 

Hopefully I can come up with a solution to my question tonight. 

Ceg, I have another question for you, sorry this is getting longer.

I will start this tank (heavily planted) all natural no ammonia addition. How often should I change the water and how much for the first few weeks of set up? 

Thank you,
Rodgie


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## DjDamo (16 Nov 2017)

Good discussion


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## ceg4048 (16 Nov 2017)

Rodgie said:


> https://www.amazon.com/gp/aw/d/B008...etailBullets_secondary_view_div_1510788321252
> 
> 
> Haha that's more complicated than I thought. I'll try to do the equation when I get home. Right now, on top is the link of the tank I'm going to purchase.
> ...


Hi Rodgie,
               Yes, it is complicated. You can add floating plants to your list to be on the safe side.
I'd suggest that you change as much of the water as you can 2 to 3 times a week. for the first month or so. When you change the water, take the water line down LOW and allow the plants to dry out a little before refilling. What this does is it gives them a gulp of air. Do the water change before the lights go on and taking the water level low and exposing them to air will help to give them a little bit of extra CO2.

Cheers,


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## Rodgie (16 Nov 2017)

Thank you Ceg,

That's a brilliant idea! I can definitely do 2-3 times a week water change. This will be interesting about draining the water low, I'll have Monte Carlo(carpet plan) so the water line will really go LOW. If I'll remove let's say 90% of the water every WC, does this mean I have to keep dosing EI dry ferts too at the same time? 

And sir, I read somewhere here today, stating that: 
Using a gassed out water for WC is good for low tech so that the tank won't have fluctuating Natural Co2. Is that correct? 

And lastly about draining the water low. Should I do this all the time too in the future? Or I can get away without it after the first two months of setting up?

I appreciate your advice always.

Cheers


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## Edvet (17 Nov 2017)

ceg4048 said:


> will help to give them a little bit of extra CO2





Rodgie said:


> I read somewhere here today, stating that:
> Using a gassed out water for WC is good for low tech so that the tank won't have fluctuating Natural Co2


These kind of go against each other don't you think? 

I wouldn't worrie about fluctuating CO2, especialy if you do the waterchange before "lights on"


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## zozo (17 Nov 2017)

Edvet said:


> I wouldn't worrie about fluctuating CO2, especialy if you do the waterchange before "lights on"



I do water change straight from the tap.. And actualy i'm not the structual type, so i do it when ever i find the time once a week about 40%. The normal and stable mid day pH value in the tank is pH 8.2 which goes down to 7.7 after lights out.. My  tap water comes from the tap at a pH 7.5. In my kH patern, even if i do the WC mid day, that would be a Co² fluctuation of about 2ppm, because 40% only make it drop to around pH 7.9 after the WC which gasses out or is used what ever in less then 2 hours. All added up, even "if" having this once a week, can't realy be called a fluctuation, not even a little bump on the road imho.  At least i do not suffer any visual negative effects in my somewhat irregula WC schedule..


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## ceg4048 (17 Nov 2017)

Edvet said:


> These kind of go against each other don't you think?
> 
> I wouldn't worrie about fluctuating CO2, especialy if you do the waterchange before "lights on"



HI Guys,
             Yes, this is a conflict, but I am taking into account the conditions. Under stable conditions, when the tank is grown in and is mature, fluctuating CO2 due to tap water levels can sometimes induce BBA, however, in my advice to Rodgie I'm taking into account the fact that he is starting the tank, so this advice is an attempt to assist the plants to adapt to being submersed and so will help to avoid melting and so forth. After the first couple months, when the plants have adapted, then the manic water changes wont be necessary.

I think people forget how aquatic plants handle submersion in natural conditions. They don't usually just get flooded in one day. The rain come and the water level rise gradually. The plant then has some leaves submerged and the highest leaves are in air, which still collect plenty CO2. Stems plants that have the ability to elongate do so to keep the upper leaves in air. The submergence of the lower leaves triggers the transformation so that by the time the water level covers the top most leaves the adaptation is well underway. Additionally, the lighting is usually reduced due to the turbidity of the water. This is the opposite of how we do it. We dump them under water ad add tons of light. Is it any wonder that we have trouble?

Cheers,


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## Victor (9 Jan 2018)

ceg4048 said:


> You can sometimes see the behavior in stem plants under high lighting/CO2. In the early part of the photoperiod the leaves are wide open to collect light:
> 
> 
> 
> ...



Hi, Ceg. My tank photoperiod 10 hours continuous (2 h low light, 6 h high light and 2 h low light again). But I noticed my rotala wallichii opens its leaves in presence of indirect sunlight (environment light), several hours before the tank lights turn on. So I assume a very small amount of light, like environment light from a window can trigger the plant to begin photosynthesising, right? Once the photosynthesis begins it'll lasts, for most plants, about 8 to 10 hours, isnt it? So if my plants begin photosynthesising from the moment their leaves open out (about 9 am) they'll "shut down" about 7 pm. And my tank lights turn on 3 pm and turn off 1 am. The same rotala wallichii I mentioned above closes it leaves 4 h before the tank lights turn off. So the conclusion is my photoperiod shouldn't running so long during the night. At least it should be from 11 am to 9 pm. This make sense?


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## ceg4048 (10 Jan 2018)

Hi Victor,
              Well it's not really clear if this has been happening for a long tie or whether those plants have just been placed in the tank. If they are new then they could be following the program from their previous location.
Long photoperiods are generally not all that useful as they can trigger algal blooms unless the intensity is low. It looks like you have set the lights to low for the last 2 hours, which is a good idea -- but how low is low? There are so many variables it's difficult to predict. In any case if you are not suffering any health issues then I would just carry on and not worry too much about it. They may even adjust  to your graveyard shift of 3PM to 1AM.

Cheers,


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