Lighting duration

[Tim Harrison]

6-8 hours photo period appears to be largely the de facto standard advice for a high tech/CO2 injected tank on this forum, particularly on a tank start-up - the reason quoted to avoid algae outbreaks

From @Tim Harrison's excellent soil substrate guide:



I 'm not sure on the origin of the 6-8 hours photo period - I've read numerous comments from Tom Barr (@plantbrain) recommending 6-10 hours. However as we now have two forum experts advocating 12 hours photo periods, it would be useful to understand where the original 6-8 hour advice comes from, and recheck its validity on a high tech tank?

I have always run my tanks with a 6-7 hour photo period, purely for the reason of avoiding algae. Even though, anecdotally, I've never had any significant issues with plants growing sufficiently in that period, I'd definitely prefer to have the lights on for 12 hours instead, providing that doesn't lead to additional algae.

I think it just comes down to a set of prescribed parameters that are likely to make life as easy as possible, especially for those just starting out on their planted tank journey. I don't think the advice is meant to be set in stone, it's a baseline starting point that gives the most wriggle room and is relatively forgiving of mistakes. Another would be the 10 x tank volume filter turnover or flow.

Beyond that, there are many routes to success. For instance, I've run soil tanks on a 12 hour photoperiod without any problems, but there's perhaps less room of maneuver and it can become a bit of a juggling act to achieve balance.

 

[jaypeecee]

As a side question to this, would a ramped lighting intensity and a difference in spectrum at certain points of the day be preferable to the plants like they get in nature?

Hi @Franks

Good question. Perhaps @Christel could give us the benefit of her extensive knowledge and experience?

JPC

 

[Christel]

Hi, I have been a passionate plant aquarist for more than 45 years. All my 11 plant aquariums with in total 4000 liters have a day length of at least 12 hours of lighting, as I cultivate many species and I use an average value for the day length. There are species such as Anubias, Bolbitis, Bucephalandra that grow in the tropical rainforest and they have a slightly shorter day length due to the shading of the trees. Therefore, it is possible to cultivate Bucephalandra even with 10 hours of day length. But even the first and last hour of the day there is still a weak daylight in the rainforest. You can learn a lot from nature, I have made many light measurements, but you also have to want to acknowledge nature as a teacher. In my book Aquarium Plants, which some of you have by now, you will find detailed information about the ecological factors of light, substrate, water etc. and of course the importance of light for culture in the aquarium. There is an extra chapter on daily lighting periods in my book. Of course, I can't write all this in two sentences. Each of you must decide for yourselves how long you choose the day length for your aquarium. But if not every plant species grows, there may be a reason for this.

 

[Wookii]

Hi, I have been a passionate plant aquarist for more than 45 years. All my 11 plant aquariums with in total 4000 liters have a day length of at least 12 hours of lighting, as I cultivate many species and I use an average value for the day length. There are species such as Anubias, Bolbitis, Bucephalandra that grow in the tropical rainforest and they have a slightly shorter day length due to the shading of the trees. Therefore, it is possible to cultivate Bucephalandra even with 10 hours of day length. But even the first and last hour of the day there is still a weak daylight in the rainforest. You can learn a lot from nature, I have made many light measurements, but you also have to want to acknowledge nature as a teacher. In my book Aquarium Plants, which some of you have by now, you will find detailed information about the ecological factors of light, substrate, water etc. and of course the importance of light for culture in the aquarium. There is an extra chapter on daily lighting periods in my book. Of course, I can't write all this in two sentences. Each of you must decide for yourselves how long you choose the day length for your aquarium. But if not every plant species grows, there may be a reason for this.

I must admit to not having had chance to sit down and read your book properly as yet @Christel, but I’m looking forward to doing so.

I hope you have chance at some point to create some entries in the journals section of this forum to show some of your tanks and outline your procedures and techniques - I for one would love to see them.

 

[Christel]

I must admit to not having had chance to sit down and read your book properly as yet @Christel, but I’m looking forward to doing so.

I hope you have chance at some point to create some entries in the journals section of this forum to show some of your tanks and outline your procedures and techniques - I for one would love to see them.

It is easy to see some of my tanks on Instagram and I am trying to give some tips for propagation and culture there. Ukaps is also on Instagram and it is easy to create your own account.

 

[Wookii]

It is easy to see some of my tanks on Instagram and I am trying to give some tips for propagation and culture there. Ukaps is also on Instagram and it is easy to create your own account.

Thanks Christel - I've just searched for you on there:

Christel Kasselmann (@christel.kasselmann) • Instagram photos and videos

6,753 Followers, 959 Following, 751 Posts - See Instagram photos and videos from Christel Kasselmann (@christel.kasselmann)

www.instagram.com

I find Instagram great for images, not so good for technical discussion.

Your 5.7m L-shaped aquarium looks incredible (I think there will be a few collective UKAPS jaws hitting the floor at this image):

 

[Christel]

Thanks Wookii, I am little bit crazy - I know (but you perhaps also?). On the other side of these tanks are 8 more...., but smaller ones (90-450 liters). I have never enough space (and never enough time) for all these beautiful plants.