# "Siesta" a.k.a 2 photoperiods



## bikinibottom (Nov 18, 2012)

I've seen many of the threads arguing the usefulness of the siesta approach (4 hours on, 4 hours off, 4 hours on) and the impacts on fish bio-rhythms. The thing that interests me about the technique is the evidence that there is more CO2 available to the plants after the "siesta". In a low-tech tank, this would seem to be a boon.

What I'm unsure about is the siesta itself and how much light the tank receives. My tank is in a finished room in my basement, and the room has only 2 windows at either end of the room at the ceiling, so the room and tank receive very little natural light in the middle of the day. In fact, on a rainy day like today it's more dark than light. Will this dark-ish siesta period negatively affect the plants or fish? Does the tank need to be near a bright window?


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## Steve001 (Feb 26, 2011)

bikinibottom said:


> I've seen many of the threads arguing the usefulness of the siesta approach (4 hours on, 4 hours off, 4 hours on) and the impacts on fish bio-rhythms. The thing that interests me about the technique is the evidence that there is more CO2 available to the plants after the "siesta". In a low-tech tank, this would seem to be a boon.
> 
> 
> What I'm unsure about is the siesta itself and how much light the tank receives. My tank is in a finished room in my basement, and the room has only 2 windows at either end of the room at the ceiling, so the room and tank receive very little natural light in the middle of the day. In fact, on a rainy day like today it's more dark than light. Will this dark-ish siesta period negatively affect the plants or fish? Does the tank need to be near a bright window?


This is a thoughtful question to ask. 
There are no hard and fast rules.
A siesta isn't a complete secession of photosynthesis, just a reduction.
Intuition suggests 4 hours off would be to long. That would make for a very long total photosynthetic period of time and a long day for the fish.
My tank runs via natural light and with supplemented artificial light. With all these variations in light intensity I've not had any problems.


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## TexasCichlid (Jul 12, 2011)

It has been pretty well documented that a split photoperiod does little to nothing in terms of fighting algae or promoting plant growth. Your best bet is to figured out how long you want your lights to run and adjust fertilizers and CO2 levels accordingly.


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## Seattle_Aquarist (Jun 15, 2008)

bikinibottom said:


> I've seen many of the threads arguing the usefulness of the siesta approach (4 hours on, 4 hours off, 4 hours on) and the impacts on fish bio-rhythms. The thing that interests me about the technique is the evidence that there is more CO2 available to the plants after the "siesta". In a low-tech tank, this would seem to be a boon.
> 
> What I'm unsure about is the siesta itself and how much light the tank receives. My tank is in a finished room in my basement, and the room has only 2 windows at either end of the room at the ceiling, so the room and tank receive very little natural light in the middle of the day. In fact, on a rainy day like today it's more dark than light. Will this dark-ish siesta period negatively affect the plants or fish? Does the tank need to be near a bright window?


Hi bikinibottom,

I run a split period on all of my tanks; that way the light is on in the morning when I feed before I leave and in the evening when I feed, do maintenance, and sit and enjoy my tanks. My plants grow great with no issues whatsoever and my fish breed regularly (Apistogramma, Rainbowfish, Angelfish, and Corydoras sp). The typical period the lights are on during the day is 8 hours.


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## bikinibottom (Nov 18, 2012)

TexasCichlid said:


> It has been pretty well documented that a split photoperiod does little to nothing in terms of fighting algae or promoting plant growth. Your best bet is to figured out how long you want your lights to run and adjust fertilizers and CO2 levels accordingly.


I'm unconcerned with the technique as a means to control algae growth. So plant growth is the primary goal. With a low-tech tank I'm not expecting a high growth rate, but just fuller, greener, lusher, healthier plants in general. Since aquatic plants are limited by CO2, Walstad's measurements with a siesta regimen, which show that CO2 levels rebound with a 4-hour siesta) are a good argument for trying this technique. 

But you're right, a higher CO2 level in the tank does not necessarily mean that the plants are going to grow better/stronger/faster/healthier. I'd be interested in seeing the documentation you're talking about that shows that the siesta regimen doesn't promote plant growth.


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## bikinibottom (Nov 18, 2012)

Beautiful tank, Seattle!! 

How long do you leave your lights on in the morning and evening? And I did I read that right -- you leave them OFF for 8 hours? 



Seattle_Aquarist said:


> Hi bikinibottom,
> 
> I run a split period on all of my tanks; that way the light is on in the morning when I feed before I leave and in the evening when I feed, do maintenance, and sit and enjoy my tanks. My plants grow great with no issues whatsoever and my fish breed regularly (Apistogramma, Rainbowfish, Angelfish, and Corydoras sp). The typical period the lights are off during the day is 8 hours.


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## Seattle_Aquarist (Jun 15, 2008)

bikinibottom said:


> Beautiful tank, Seattle!!
> 
> How long do you leave your lights on in the morning and evening? And I did I read that right -- you leave them OFF for 8 hours?


Hi bikinibottom,

My lights are on for about 2.5-3.0 hours in the morning and 3.0-3.5 hours in the evening; I have them on timers. Yes, the siesta period is approximately 8 hours from about 10:00 AM until about 6:00 PM. I have done this for about 4 years now.

30 gallon split period


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## TexasCichlid (Jul 12, 2011)

bikinibottom said:


> I'm unconcerned with the technique as a means to control algae growth. So plant growth is the primary goal. With a low-tech tank I'm not expecting a high growth rate, but just fuller, greener, lusher, healthier plants in general. Since aquatic plants are limited by CO2, Walstad's measurements with a siesta regimen, which show that CO2 levels rebound with a 4-hour siesta) are a good argument for trying this technique.
> 
> But you're right, a higher CO2 level in the tank does not necessarily mean that the plants are going to grow better/stronger/faster/healthier. I'd be interested in seeing the documentation you're talking about that shows that the siesta regimen doesn't promote plant growth.


My documentation is "Tom Barr said so" - Don't have a link, but it was either here or on his website.


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## Steve001 (Feb 26, 2011)

I find it necessary to voice an opinion here. That opinion is; it seems some folks, since I've joined this forum, treat their tanks as if they are simply ornamentation's rather than living systems that deserve a greater degree of respect. Such perceptions of attitudes makes me wonder if this is the right hobby for certain people and what reasons they got into this hobby. It reminds me of rich folks that buy dogs simply as accessories.


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## TexasCichlid (Jul 12, 2011)

Steve001 said:


> I find it necessary to voice an opinion here. That opinion is; it seems some folks, since I've joined this forum, treat their tanks as if they are simply ornamentation's rather than living systems that deserve a greater degree of respect. Such perceptions of attitudes makes me wonder if this is the right hobby for certain people and what reasons they got into this hobby. It reminds me of rich folks that buy dogs simply as accessories.


All sorts of enthusiasts. Some people just want to grow plants in farm tanks and sell them. Some people want to have the nicest looking hardscape. Some want a jungle. Fauna, in all cases, may simply be optional beyond cleaner critters. Some may be only interested in adding a particular aesthetic to a room. I don't think anyone has the right to stand up and proclaim that the way they approach the hobby is any better than how someone else chooses to do so.


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## Tenor1 (Jan 15, 2012)

Steve001 said:


> I find it necessary to voice an opinion here. That opinion is; it seems some folks, since I've joined this forum, treat their tanks as if they are simply ornamentation's rather than living systems that deserve a greater degree of respect. Such perceptions of attitudes makes me wonder if this is the right hobby for certain people and what reasons they got into this hobby. It reminds me of rich folks that buy dogs simply as accessories.


This seems like a harsh accusation of fish abuse and maybe I'm completely misinterpreting it. I had the same question on a split-lighting schedule. Asking the question is a testament that there is concern for doing the right thing. I want to optimally enjoy and view my tank when I'm in the room. But I would like to know if there is any detriment to either flora or fauna with a split-lighting system. If there is any detriment, then I wouldn't want to do it.

There is a dimmer system that turns the lights on/off gradually so there is no shock to the fish. This is the reason I'm responding to this thread.


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## scbrooks87 (Nov 28, 2012)

Steve001 said:


> I find it necessary to voice an opinion here. That opinion is; it seems some folks, since I've joined this forum, treat their tanks as if they are simply ornamentation's rather than living systems that deserve a greater degree of respect. Such perceptions of attitudes makes me wonder if this is the right hobby for certain people and what reasons they got into this hobby. It reminds me of rich folks that buy dogs simply as accessories.


I do think this is an opinion that should be voiced, and a valid concern within the hobby, however I'm not convinced that this thread fits the bill for that concern...

This person was merely looking to find out if a break in the lighting period is beneficial, detrimental, or has no effect.

Now in some threads, where people speak of their tanks, and the inhabitants as a decoration, rather than as pets, and just want to know how to make it a prettier decoration, no matter how it could harm the living creatures inside, that's where I think this opinion should be brought to light.

Just my $0.02


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## wkndracer (Mar 14, 2009)

TexasCichlid said:


> It has been pretty well documented that a split photoperiod does little to nothing in terms of fighting algae or promoting plant growth. Your best bet is to figured out how long you want your lights to run and adjust fertilizers and CO2 levels accordingly.


Wow! whoa there horsie! hahaha! my favorite TB statement was this one:
"Never a one trick pony". I've noticed not everyone tanks with an adjustable CO2 system. 


bikinibottom said:


> I'm unconcerned with the technique as a means to control algae growth. So plant growth is the primary goal. With a low-tech tank I'm not expecting a high growth rate, but just fuller, greener, lusher, healthier plants in general. Since aquatic plants are limited by CO2, Walstad's measurements with a siesta regimen, which show that CO2 levels rebound with a 4-hour siesta) are a good argument for trying this technique.
> 
> But you're right, a higher CO2 level in the tank does not necessarily mean that the plants are going to grow better/stronger/faster/healthier. I'd be interested in seeing the documentation you're talking about that shows that the siesta regimen doesn't promote plant growth.


Well worded reply roud: 


TexasCichlid said:


> My documentation is "Tom Barr said so" - Don't have a link, but it was either here or on his website.


:hihi:

It's always best to remember,,, never say never,,,, never say always.

Those that are devoted to the MTS enriched soil method state organic content is to be avoided and causes problems. NPT depends on the soil organics as part of that method, polar oposites of opinion with the same goal.

Different tanking conditions would modify the results and or possible benefits. Having a lot of surface disturbance or running air pumps to drive air stones the CO2 rebound would be nullified. Comparing NPT to injected CO2 methods is mixing into a debate like which is better,, apples or oranges? It's a personal choice of method not a race.

I run split photo periods on a number of tanking systems and have for about 3 years. The average is about 8-10 hrs. between photoperiods. Whether my fish think they are twice as old as they are in reality because they 'see the sun' twice a day I don't know :hihi:. But things appear good.
Plants growing, shrimp and fish spawning and producing young. As long as the system has a rest period and consistent schedule I think all parties adapt to the environment. 

(note) I did start splitting the photoperiod on low light tanks to help with thread algae and think it helped along with other adjustments. Ignoring the rest of the thread topics LOL


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## minicrazy592 (Apr 1, 2010)

My tank's lights start at noon. Both rooms with tanks are lighted with sunlight so this could be seen as a "burst" if you will. They stay on for 3 hours and then are off for 1 hour. Mind that the sun is still shining bright into the rooms. Then it will come on again for another 4. I tack the extra hour on there so I can get home in time for feeding. Does it make any difference in algae? I can't say for a fact, but when I'm running 60-80 par on the substrate I think it may help the plants to "take a break", if you will, from the lights.


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## bikinibottom (Nov 18, 2012)

Steve001 said:


> I find it necessary to voice an opinion here. That opinion is; it seems some folks, since I've joined this forum, treat their tanks as if they are simply ornamentation's rather than living systems that deserve a greater degree of respect. Such perceptions of attitudes makes me wonder if this is the right hobby for certain people and what reasons they got into this hobby. It reminds me of rich folks that buy dogs simply as accessories.


I always appreciate hearing the opinions of others, although I can't say I understand what yours is in this particular case. Is it your opinion that splitting photo periods is detrimental to fish health? If so, I'd be interested to know on what you base your opinion. I've seen a plethora of anecdotal evidence that it does not harm the fish. In fact, I've seen some of that evidence in this very thread (fish on split photo periods are healthy, eating, spawning, etc.)

I didn't get into the hobby to torture fish. I got into the hobby because I like fish, and invertebrates, and plants, and water, and soil, and light... you know, all the things that make up "the system". Fish AND plant health are among my goals. If I didn't care about that then I wouldn't have even asked the question as to whether anyone is aware if splitting photo periods was detrimental.


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## Tenor1 (Jan 15, 2012)

bikinibottom said:


> I always appreciate hearing the opinions of others, although I can't say I understand what yours is in this particular case. Is it your opinion that splitting photo periods is detrimental to fish health? If so, I'd be interested to know on what you base your opinion. I've seen a plethora of anecdotal evidence that it does not harm the fish. In fact, I've seen some of that evidence in this very thread (fish on split photo periods are healthy, eating, spawning, etc.)
> 
> I didn't get into the hobby to torture fish. I got into the hobby because I like fish, and invertebrates, and plants, and water, and soil, and light... you know, all the things that make up "the system". Fish AND plant health are among my goals. If I didn't care about that then I wouldn't have even asked the question as to whether anyone is aware if splitting photo periods was detrimental.


Here, here,


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## bikinibottom (Nov 18, 2012)

This really is a pretty fascinating topic. It's too bad there aren't more controlled experiments out there that measure different plant types under different lighting regimes. I'd imagine it's too monumental a task with too little payoff given the variety of lighting types and plants, and the number of factors that would impact plant growth (source water, substrate, dosing, stocking, interaction with other plants, etc.)


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## thesawguy (Dec 26, 2011)

I can understand the lure of a split cycle for viewing purposes for a working individual but one thing to consider is that turning fluorescent lights on and off twice as often will shorten their useful life, wearing them out faster.


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## Seattle_Aquarist (Jun 15, 2008)

thesawguy said:


> I can understand the lure of a split cycle for viewing purposes for a working individual but one thing to consider is that turning fluorescent lights on and off twice as often will shorten their useful life, wearing them out faster.


+1 on thesawguy's comment; split periods do shorten the life expectancy of fluorescent tubes. Because I have found the output of my bulbs typically drops by 25% or more over a 12 month period (verified with PAR meter readings) I change my bulbs annually and seldom have a bulb fail prior to replacement.


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## gordonrichards (Jun 20, 2009)

I am a firm believer in siesta and run 4 hours on, 2 hours off, 4 hours on.

This method will help keep algae problems in check.

If its not a factor, you could just run your lights for 6-7 hours a day.

-g


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## bikinibottom (Nov 18, 2012)

Thanks for all the replies -- I'm pleased to hear so many people seem to have success using the split photo period. Getting back to my original question, I'm wondering about whether there is such a thing as "too dark" for the siesta. It seems like many of the people employing the method have their tanks next to windows and are therefore getting a fairly good amount of natural light in the middle of the day. My tank is in a finished, partially-underground basement room where the windows are at the ceiling, above the tank, so the room gets *some* natural light, but it's a pretty dimly lit room when the lights are off. On a dark, cloudy day I can barely even see what's going on inside the tank when the light is off. Does anyone think this is "too dark" for a siesta?


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## Seattle_Aquarist (Jun 15, 2008)

Hi bikinibottom,

My tanks are in a my lower level office with one 1/2 height window.


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## bikinibottom (Nov 18, 2012)

Seattle_Aquarist said:


> Hi bikinibottom,
> 
> My tanks are in a my lower level office with one 1/2 height window.


Good to know, Seattle! Thanks again! I'm so grateful this forum is here and that folks are so willing to share their knowledge and experiences.


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## Steve001 (Feb 26, 2011)

TexasCichlid said:


> All sorts of enthusiasts. Some people just want to grow plants in farm tanks and sell them. Some people want to have the nicest looking hardscape. Some want a jungle. Fauna, in all cases, may simply be optional beyond cleaner critters. Some may be only interested in adding a particular aesthetic to a room. I don't think anyone has the right to stand up and proclaim that the way they approach the hobby is any better than how someone else chooses to do so.





Tenor1 said:


> This seems like a harsh accusation of fish abuse and maybe I'm completely misinterpreting it. I had the same question on a split-lighting schedule. Asking the question is a testament that there is concern for doing the right thing. I want to optimally enjoy and view my tank when I'm in the room. But I would like to know if there is any detriment to either flora or fauna with a split-lighting system. If there is any detriment, then I wouldn't want to do it.
> 
> There is a dimmer system that turns the lights on/off gradually so there is no shock to the fish. This is the reason I'm responding to this thread.


In my first reply, I did let the op know they had asked a thoughtful question.
My post wasn't directed at the op certainly or anyone in particular though one poster did prompt this response that I've been thinking about on and off recently. Maybe this is a topic worth discussing. I could start a new thread.


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## bikinibottom (Nov 18, 2012)

Steve001 said:


> In my first reply, I did let the op know they had asked a thoughtful question.
> My post wasn't directed at the op certainly or anyone in particular though one poster did prompt this response that I've been thinking about on and off recently. Maybe this is a topic worth discussing. I could start a new thread.


Sorry, again... not following you. If your comment wasn't directed at anyone in particular, but is in response to what one of the posters said, I still don't see it. Are you referring to people planning a split photo period for the sole purpose of viewing their tank? I really do want to understand you. I'll be interested in seeing your new thread if you decide to start one.

Steve001, I do agree with you that some of the posters in the forum can be revolting the way they talk about their tanks as if fish loss is just a financial loss or a hassle. But I really didn't see that in these posts. And the quotes you quoted in your last post were quotes made in response to your comment, which seemed misplaced in this thread. TexasCiclid pointed out that there are all kinds in this hobby, all entering the hobby for different reasons, with different goals in mind. Like it or not, that is what we've got. And none of us are "innocent", because there's nothing "natural" about what we're doing, let's face it. A plant from Indonesia, a fish from South America, substrate from a bag, all thrown into a glass tank filled with municipal water and illuminated by fixtures powered by coal-fired electricity.


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## Steve001 (Feb 26, 2011)

bikinibottom said:


> Sorry, again... not following you. If your comment wasn't directed at anyone in particular, but is in response to what one of the posters said, I still don't see it. Are you referring to people planning a split photo period for the sole purpose of viewing their tank? I really do want to understand you. I'll be interested in seeing your new thread if you decide to start one.
> 
> Steve001, I do agree with you that some of the posters in the forum can be revolting the way they talk about their tanks as if fish loss is just a financial loss or a hassle. But I really didn't see that in these posts. And the quotes you quoted in your last post were quotes made in response to your comment, which seemed misplaced in this thread. TexasCiclid pointed out that there are all kinds in this hobby, all entering the hobby for different reasons, with different goals in mind. Like it or not, that is what we've got. And none of us are "innocent", because there's nothing "natural" about what we're doing, let's face it. A plant from Indonesia, a fish from South America, substrate from a bag, all thrown into a glass tank filled with municipal water and illuminated by fixtures powered by coal-fired electricity.


Lets start a new thread and not derail this one.


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## TexasCichlid (Jul 12, 2011)

gordonrichards said:


> I am a firm believer in siesta and run 4 hours on, 2 hours off, 4 hours on.
> 
> This method will help keep algae problems in check.
> 
> ...


Do you keep your CO2 going during the siesta?


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## Seattle_Aquarist (Jun 15, 2008)

Hi TexasCichlid,

On the tanks that have CO2 I keep the CO2 running.


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## TexasCichlid (Jul 12, 2011)

Thanks. I will give this method a shot and see if I notice anything different. My only concern is gassing my tank during the siesta. How long do you give the CO2 time to build up before lights on initially, and when do you turn the CO2 off prior to final lights out?


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## Seattle_Aquarist (Jun 15, 2008)

TexasCichlid said:


> Thanks. I will give this method a shot and see if I notice anything different. My only concern is gassing my tank during the siesta. How long do you give the CO2 time to build up before lights on initially, and when do you turn the CO2 off prior to final lights out?


Hi TexasCichlid,

I run my CO2 24/7; CO2 is cheap and that way I don't worry about solenoid failure.


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## Steve001 (Feb 26, 2011)

TexasCichlid said:


> Do you keep your CO2 going during the siesta?


I have an open top tank and run the co2 non stop. I've been doing that for over two decades. Light also varies because most of the lighting is natural with some supplemented lighting. During the Spring-early Fall it's all natural lighting. Not once have I had a problem with co2 gassing of fauna. The key here, may be do to co2 having an easy way to escape in contrast to a closed topped tank.


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## CJKlok (Nov 23, 2010)

Prior to running my tanks with a 3 hour siesta - lights on at 7:30, and off for the night at 20:00 - I had green spot algae growth giving me spots of about 3 to 4 mm in diameter every week. Thus, scraping spots on Saturday, in between other regular maintenance tasks, only to have the 3 to 4 mm spots growing back by the next weekend.
Then, reading that a break in lighting regime could interfere with the algal cell cycle - which requires 6 to 8 hours to complete - I decided to implement a siesta. So I set it at: lights on at 7:30, off at 12:00, on at 15:00 and off for the night at 20:30. 
Since then the number of spots decreased noticeably, and their diameters never exceed 2 mm. This reduced maintenance significantly. Also the growth of other algal species - hair alga, black beard and the common green furry algae - decreased. This then also reduced the requirement for chemical control - spot treatments with either hydrogen peroxide or excel.
And I had no ill effects on fish or inverts yet.


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## bikinibottom (Nov 18, 2012)

This thread has me thinking about doing a small experiment. Not really an "experiment", since I can't set up very many tanks, but I was thinking about the possibility of setting up 3 identical 5 or 10-gallon tanks -- same substrate, same plant species, one type of fish, same dosing regime (if any), same feeding schedule, etc.) -- but have 3 different lighting schemes. The control tank would run a standard 12-hour photo period from 7 to 7. The other 2 tanks would run split photo periods (4 on, 4 off, 4 on, starting at 7 am), but one would be in a dimly lit room, and one would be in a brightly lit room.

The purpose would be to observe the rate of plant growth, algae growth, and fish behavior. Anyone have any thoughts on how to measure/describe these things? Especially "fish behavior". And if you have any thoughts about the design of the experiment I'd be interested to hear them. Might need to do a separate thread....


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## james1542 (Sep 8, 2011)

That's a great idea. if you had 6 tanks and just 2 treatments you could do a t-test. Just do a 6+6 siesta vs a 12 hour photoperiod. For the sake of the experiment I would start with no co2, you could run a second experiment afterwards with co2 in all the tanks, or maybe excel. If you have a small scale that would help. 

For response variables-You could measure plant weight, or plant height. Riccia is a good one for plant weight, or some java moss. Have a single crypt of the same species in each tank, weigh or measure them before and after. Also a stem plant would be good to include. Something easy and fast growing to get clear results. You could also count leaves on the crypts or swords. Fish would be much more difficult. If the tanks were large enough, guppy colonies would be hard to beat. Their population size after a few months would be a good indicator, as would their weight if you had a fine scale to weigh them. Algae would also be very hard to quantify. You might be able to quantify the % coverage on the glass or something like that, but I think it would end up being more like a subjective thing. Maybe for BBA you could count the number of threads on all your plant leaves? That would be pretty solid.


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## bikinibottom (Nov 18, 2012)

james1542 said:


> That's a great idea. if you had 6 tanks and just 2 treatments you could do a t-test. Just do a 6+6 siesta vs a 12 hour photoperiod. For the sake of the experiment I would start with no co2, you could run a second experiment afterwards with co2 in all the tanks, or maybe excel. If you have a small scale that would help.
> 
> For response variables-You could measure plant weight, or plant height. Riccia is a good one for plant weight, or some java moss. Have a single crypt of the same species in each tank, weigh or measure them before and after. Also a stem plant would be good to include. Something easy and fast growing to get clear results. You could also count leaves on the crypts or swords. Fish would be much more difficult. If the tanks were large enough, guppy colonies would be hard to beat. Their population size after a few months would be a good indicator, as would their weight if you had a fine scale to weigh them. Algae would also be very hard to quantify. You might be able to quantify the % coverage on the glass or something like that, but I think it would end up being more like a subjective thing. Maybe for BBA you could count the number of threads on all your plant leaves? That would be pretty solid.


Thanks, hadn't thought about the statistical analysis but a t-test makes sense. What do you mean by a 6+6 siesta, though? 6 on, 6 off, 6 on, 6 off? 

I would keep the plant species to one so that interactions among plants aren't an issue (for example, one taking up more nutrients than the other).

I like the idea of guppies/population size for measuring the fish, but that could get tricky if you happen to throw in, say, 3 females that are on the verge of having babies in one tank versus 3 that just had babies. Instead of total population size I guess you could instead count how many fry are born, how many survive, etc., although from experience it's kinda hard counting all those little things! 

What about fish behavior? What would be a less-subjective way to describe that? I'm curious to know if the split photo period stresses the fish, so I'm wondering if there are specific behaviors to observe.


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