Lighting brake

[aix]

There is a new theory with lighting which is used for planted tanks. It seems that turning the lights off for 1-1,5 hours a day plants grow better because in the dark some additional CO2 can develop and algae can not usually survive. So no algae and plants have some CO2 for evening time when they usually have too little of CO2. So 2 plusses with one move. I just would like to know if anybody is using this system already and what are your observations? I started this system yesterday so it would be good to know what am I facing.

[ChloroPhil]

Not at all.

Your plants need a full 10-12 hr photoperiod. If the light goes out they stop photosynthesizing and it takes them a while to get back up to speed. In that time the algae, who are much quicker, will take advantage of the good conditions and will grow.

[aix]

That has been my understanding also but still at least in Germany and also Finland some of the best plant specialists are using this system and are recommending it. This observation is rather new so I can not comment yet (common sence says one thing, specialists another)

[ronrca]

I have heard of it. It is based on the theory that in the tropics, most often the is a period where the clouds form and short showers. Im actually testing it right now with my 90G. So far it has not proved to be successful rather massive algae growth. I'll test it for another month or two yet.

[ChloroPhil]

Even during storms there is more light than we're putting into our tanks... Food for thought.

[aix]

Just checked and some aquarists even use 3h brake to make it possible to keep lights on late at night (when is the best time to enjoy under water world). For example lights are on 8-11 and again 14-23. So far in my "test tank" this experiment is everything but successful. But patience is everything in aquaristics.

[ChloroPhil]

What kind of plants are you keeping in your aquarium and how much do you fertilize?

[jeff cannons]

Hi Guys I've been using the lights out method on my tank since I set it up in febuary and I'm having no problems the fish are fine the plants are doing really well and guess what no algae, the german company Dennerle whos fertilizer and products I use recomend it . ::)

[chirohorn]

Aren't we trying to replicate nature? Here in Texas, we're getting ~14 hours of daylight...with no interruptions.

[joelfish]

Jeff Cannons - did the lights out method solve a problem (algae?) or are you just successful with it?

If the goal of this is to increase CO2 levels, it would seem better to increase CO2 input to balance nutrients and light - instead of turning off the light?

Maybe there are afternoon storms on many days, but I wouldn't think that the darkness would be anywhere near that of a planted tank with the lights off.

As we all know, many plants in the wild grow above the water where they get a direct hit of light, unfiltered by water. Also, our bulbs peak at certain wavelengths, whereas sunlight is a continuous spectrum. I would think that with 12 hrs of continuous light, we're still giving only a fraction of the photosynthetically active radiation that they get in the wild - so why limit it even more? That is, unless the nutrients and CO2 levels aren't up to the level of light?

'Brake' indeed..... I prefer to hit the gas! ;D

Maybe I'm all wet? :o

Joel Fish

[jeff cannons]

Hi Joel No I didnt have a problem with algae I set up a new tank from scratch using Dennerles book and did it on there recomendation because I'm running 2x 125w Mercury Vapours I thought I'd see how it went and everythings fine plants doing really well, fish are not botherd by it so I'm still doing it that way .

[joelfish]

That's cool. If it ain't broke......
;D

[kenoz]

In all of my display tanks I use CO2 and 12 hours light per day. The algae growth was not too bad - a few ottos help. However I read in Peter Hiscock's book "Encyclopaedia of Aquarium Plants" on page 59 to employ a siesta during the day for up to 2 hours. I've been doing that for a month now in all tanks, and the result is remarkable! The theory is that plants can resume photosynthesis very quickly, but not algae which is a less advanced organism.

Maybe ronrca's earlier comment explains how nature handles it.

Anyway, I have lights on from 8:30 - 1, off till 3, then on till 10:30 or so. The echinodorus species I have are sporting beautiful, algae free growth. I don't think I've seen my crypts looking better.

[aix]

It seems that plants need a bit time to get used to new system. 2h brake is starting to work out OK. But I am wondering about the fish- every sudden illumination (which they face every morning) seems to be a stress source for fish. Lighting brake doubles this, since the lights go on twice a day. How are your fish handling it?

[Sketchy]

...I think what we are really addressing here is simply reducing the length of lighting time to reduce the growth of algae. Plants can resume photosynthesis once the lights go back on as it is a light dependent process. Cutting out the light from 1 to 3 simply reduces the hours ones tank is lit. There is ambient light during those hours so the fish and tank are not in total darkness and the photosynthesis doesn't stop as if the tank were in a night time situation. If you want proof, watch your largest cryptocorynes open and close with the light levels, much like a flower opens as the sun rises and closes as the sun sets. A two hours break in the light cycle does not cause the crypt to close up. If you are turning on the light at the same time and turning it off at the same time, the break is simply a time reduction and is one of the oldest known ways to control algae growth.

[kenoz]

Sketchy makes a good point - the plants really don't mind but clearly the algae does. Funny, though, I've been an aquarist for many years and only recently heard about the siesta treatment for algae.

My fish aren't fussed with lights switching on and off, because there is some ambient room light for the morning and afternoon siesta not to cause a problem. In the late evening I simply shut down 1 or 2 tubes per tank which simulates dusk. Even if you don't do that, the fish shouldn't become startled. I have discus in all of my planted tanks, and they don't fuss about anything much once they've become acustomed to routine (unless meal times are delayed, of course - lol). Ken

[Sketchy]

...it really doesn't matter when that break in lighting comes -
it's just important that it comes. You can turn out the lights two hours earlier or turn them on two hours later and it will still have an effect on the growth of algae and your plants will be alright.
...case in point ---> I recently improved the lighting on my
tank and within a week and a half, noticed an algae bloom.
I had increased one of the critical factors without considering the entire nutrient relationship circle. Since the algae was growing and the plants showed no sign of nutrient deficiency, I had to assume they were getting the fertilizer nutrition they needed. I started to turn the lights on later than I had been doing and I increased the CO2 injection. Lo and behold, the algae dissappeared quickly once the lighting, the ferts, and CO2 came into balance
again.
...here is a link that Tom Barr gave me full of great information regarding planted tanks.

http://www.brainyday.com/jared/aquarium/info.htm

I always find something useful there.

[kenoz]

Excellent link. Some very good pages to ponder there.

[ChloroPhil]

I'd like to throw something out there for y'all to chew on...

Other than stopping photosynthesis what is a break in light doing? How do plants respire when there is no light and what do they put off?

Photosynthesis- 6CO2 + 6H20 = C6H12O6 (Glucose) + 602 (byproduct)

In the dark plants use O2 to respire and put off CO2 which can dramatically raise the CO2 levels in a well planted aquarium. Add large plants such as the Echinodorus in Jeff's aquarium and they're releasing a LOT of CO2 back into the system in that period. When the lights come back on the CO2 levels are higher, helping the plants grow for the next lighting period.

As a rule algae can live on much lower light and nutrient levels than our higher plants. Algae will grow in an aquarium that's "lights out" as long as there's some source of ambient light. Unless your aquarium is in a place where there is no external light source when a break in the light cycle occurs you're in truth creating a period which is beneficial to algae but not plants. Algae don't do well in environments high in O2. With the plants using up O2 during a lighting break you're again helping to create a more algae-friendly environment.

Back to the above statement on respiration and CO2/O2. It takes plants a great deal of energy to restart photosynthesis. By making the plants restart twice a day they're wasting energy which would be better used in photosynthesis and growth. Since algae have pretty much instant access to nutrients in the water column the plants' restart period is even more beneficial to them keeping in mind the fact that they can utilize the ambient light and don't have to restart like the plants do.


In conclusion:

Increasing supplimentation of CO2 and keeping a constant 10-12 hour photoperiod will provide results along the line of, but more favorable to the plants, than a break period in the lgiht cycle.

[aix]

I think now would be the time to say that lighting brake works. No algae, plants (swords) are growing fast, all is OK. But funny thing, new leaves on swords are with different shape compared to the old ones.

[ronrca]

Well lucky you! I have to change back to the constant duration after 3-4 months because my plants were dying and algae taking over. I guess it really depends on the tank and the plants. Im glad that it worked out for you! ;)

[aix]

To be perfectly honest the efect is amazing - at the moment I have 3 Ech species blooming. At the same time Ech. rose, Ech.schluetteri and Ech.osiris "rose". Each one has over 20 blooms and they are bigger than before, in diameter of 2,5 - 3cm. Very beautiful sight. I took some pictures also, just hope they come out OK.

[kenoz]

After nearly 8 weeks of trial with a mid-day break, I am getting positive results, and the plants are flourishing - unfortunately no blooms on the swords yet. That sounds spectacular! Can't wait to see the photos aix.
The only other thing I think helps is a couple of Ottos - I have 3 in one 150ltr tank, and 2 in the other. They definitely help keep the broad leaf plants clean, without doing any damage. Ken

[Sketchy]

...as for the oto's, IMO, Flying Foxes are better at keeping the algae under control.

[aix]

Hm, can not really understand why some people seem to get this system to work and others don't. Could the reaction be different in different water. Or perhaps something different with lighting? I'm using currently 3-step system(sunrise, mourning, midday) and I am giving plenty of "warning" before "dark age". Perhaps this helps plants? Or could this effect be different on different plants? ???

[ChloroPhil]

I think it's the type of plants to an extent. More likely it's the density of planting and fertilization regimen that's affecting it most. A less dense tank which needs less fertilization will likely handle a lighting break better.

[aix]

It can be. But on the other hand I think I should send you some pics from my tank. I have 4 over 70cm high swords plus 15 lower ones in my 500l tank. I prefer this way because big swords have leaves that cover direct light and fish are much bolder this way. I will sell some big ones soon (1 80cm osiris rubra and 1 70cm Rose are going for sale) so that I can grow new ones bigger (some pocket money).

[aix]

Phil, could it be that lighting brake system does not work if you add CO2 or there is plenty available already? Lighting brake gives plants some extra CO2 by reversing processes but with adding CO2 there is no need? If plants have enough CO2 in my oppinion the damage should be bigger than gain. Am I correct?

[ronrca]

Hmmm!
Lighting brake gives plants some extra CO2 by reversing processes but with adding CO2 there is no need? Not sure because the number of hours that the lights are on/off is the same! The only difference being that the plants use 02 instead of C02 in the middle of the 'normal' lighting duration. Dont know how much of an impact makes.

Update on my tank! A couple of weeks ago I change back to the 10 hours of consist lighting duration and the algae is reducing. Weird! ???

[ChloroPhil]

Doesn't surprise me at all Ron..:)

Aix,

I doubt there would be a "need" at all, but with external, or mininal, CO2 injection any dark period would work to increase the CO2 in solution.

[aix]

I have pH 8 and KH 5,5 for tapwater and there is almost no available CO2 (according to my information that is). So I usually use CO2 feeding but just for educational reasons I'm trying without it. And plants grow much better with light brake. I have moved from 2 to3 hours per day. Not sure how it will work.

[ronrca]

You dont have any welding supply shops around perhaps?

[aix]

You mean, since my water is such? No welding shops, I live outside of town. Only private houses.
After using CO2 injection for some years I thought there must be a way to grow plants without it in such water. Lucky are the people with pH6,9 and dKH 10(free CO2 over 50mg/l), it's a plant dream. With my water lighting brake has brought good results- plants are growing almost as good as with CO2 injection, and I've never seen blooms like I had some time ago. Which is strange, since I've understood that swords require continious lighting to bloom. Well, this theory is crushed. They bloom extremely well with 11h lighting with 2 hour brake.
Funny thing is that even with CO2 I had some minor problems with algae- red and thread-like green algae(don't know the names) but some weeks after new lighting system they all disappeared. So now I am changed to see what 3h brake brings along. Fish seem to be not affected by doubled "starts".

[aix]

What do you do with undergravel heater in summertime when it is too hot to use it. I have heard it is not good for it if it just stays there.

[ChloroPhil]

If the gravel gets warm in the summer the heater will usually just stay off. It's not useless just sitting there as it will turn on whenever the temperature goes back down.

As far as I'm concerned, and strictly in my own opinion, undergravel heating coils are pretty much useless, especially for discus tanks. Most of the plants we keep have strong root systems which pull water and nutrients into the substrate constantly. One medium/large sword plant will have a root system which reaches through most of the aquarium by the time it's grown that large. Tom Barr has postulated that such a plant, or group of plants, can pull as much as a full liter of water into the substrate in a day. That's a LOT.

That's not to say that if you have the coils it's time to take them out. I just wouldn't put a great deal of stock in them as a nutrient transporter in the presence of large plants.

Best,
Phil

[aix]

Thanks for this info, Phil. In the past I have noticed that in colder tanks (22C-24C) under gravel heating makes plants to grow better, I don't know, perhaps they like warm "feet". In a discus tank however, where it is very warm already, I am wondering if it can be perhaps a negative thing considering plant growth.

[ChloroPhil]

AHHHH! 600 posts!!!

Aix,

The whole concept behind substrate cables is to provide a convection current in the substrate. This is done by warming the water in portions of the substrate, causing it to rise and be replaced by the cooler aquarium water. This current not only brings nutrient laden water to the substrate, but also creates a gentle current which helps cause sediment to settle toward the bottom faster and reduce anaerobic patches.

This is believed to create a more stable and nutritious substrate. To give a little history on the subject:

As with most things in the aquarium hobby this trend started in Europe quite a few years before it became popular in North America. At that time (1980s) most European aquariums used nutrient poor substrates with a Laterite amendment and hardy plants. The lighting, CO2, and water column fertilization supplimentation wasn't (and still isn't usually) at the insane levels we in the US like to have. (More IS better, right?)

Taking into consideration the higher ratio of rooted to stem plants and the slower growing nature of most of these aquariums made the use of substrate coils a more attractive option. They weren't using 100% rich substrates and weren't supplimenting the water column to the degree that just about every nutrient was available through the leaves.

With current advances in lighting technology and better understanding of plant physiology and nutritive needs the benefits of substrate heating coils is greatly reduced. Even though I believe they're an unnecessary expense there are benefits of heating coils, especially in the typical planted discus aquarium.

Benefits:
1. Constant current greatly reduces anaerobic areas.
2. The substrate is arguably more stable over the long term.
3. Plants have greater access to nutrients at their roots than without a cable.
4. The substrate is better able to reduce nutrients to a plant friendly state.

Cons:
1. VERY expensive.
2. Plants with extensive and powerful root systems draw a lot of water.
3. The O2 released by roots produces areas of aerobic activity.
4. They can be cut, possibly electrocuting you and your aquarium.
5. Modern substrates are much

Hope this sheds a little light on things...

Phil

[aix]

First of all, congratulations on your "big number". I have my own today, not so important but still one does not reach 25 every day 8)

But your post was very interesting. Some things I knew some did not as usual. I have thrown out bottom heaters since 8 months a year my room is so warm that heater does not have to work. So I was afraid it would rust. One little usual heater does the job also very well.

Also another question to you- this light brake does not have a good efect on every sword- Ech.grisebachii is suffering a lot. Perhaps it is a general problem that light does not reach them but it seems that some species like this brake better than others. Have you had any problems with grisebachii (what is its name in english?) and what has helped you. My tank is 55cm deep so perhaps I should add reflectors? Just afraid that this would unbalance my system and I would have to put CO2 injection back. What do you think- I have 4* 58W lamps on 500l, will the reflectors provide too much light (algae problem)?

Best regards,
Ailar

[ChloroPhil]

E. grisebachii is what I know it as. :) If your plant is suffering under the lighting break method then stop doing a break (with all else being the same) and see what happens. I wouldn't add any more light, but reflectors are always a nice thing to have. As far as CO2, well, you know how I feel about that.

Happy Birthday!!!
Phil

[aix]

Thanks, Phil!

What comes to plants and lighting brake then I've had it and yesterday I draged CO2 balloon back and I will now test with lighting brake +CO2. I hope Grisebachii will like this one better. Would not like to give up the brake since this way I can observe fish in the mourning and in the evening also (I'm away a long time). But if it is necessary... OK, will order reflectors to give small plants more light.

Best regards,
Ailar