# Fully dimmable LED light settings question



## Flukeworld (20 Apr 2021)

Hello,

I've been looking for an answer across the webs, even here I have read a lot of posts but still something is bothering me without an answer. So, I decided to ask instead of trying to reinvent the wheel.

*With modern LED lightning where you can change the intensity of each light color what is the "recommended" periods and settings?*

To rephrase the question - default factory settings run as "sunrise light", "morning light", "day light", "sunset" and "night light", so where the "8 hours of light" advice is fitting into this as factory light settings are over 12 hours of lightning. Is the "day light" - max intensity light with the strongest white light setting needs to be within those 8 hours? Or, the other lower intensity periods, for example having strong red light for 12 hours is adding to the equation. I am at the point to drop off the cool tweaking light intensity feature of my expensive LED just because I cant figure this out and the plants seem not thriving as expected. I am sure I have more problems than the light, for sure unstable CO2 which I keep tweaking, but also seeing my scape getting some green/brown algae dots hinting my lightning is not okay. I know I can experiment and find my way, but I feel like having too much gadgets and options to tweak..

More info about my tank:

Its 170 liters, real volume is around 130 as I have 28 kilos of Dennerle scapers dirt with 1sm of Dennerle 9+1 enriched substrate under it, also some stones and scape.
I use EI fertilizations from home made dissolved salts - Nitrates, Phosphates, Iron and Micro elements. I tried ferting a lot, then lowered it, now I keep the recommended dosage (I believe). My floating Pistia is my "duck weed index" indicator, which seems is thriving.
I have soft tap water(GH4, KH2), so I add branded salts to increase GH to 7 and KH to 6.
I have Fluval 407 external filter which seems to be more than needed and keeps the water crystal clean with a good flow for the tank volume.
My light is 2x ZetLight Lancia2 ZP4000-895PW 36W Plant (6400LM in total). I start the light at 9AM, around 5% of intensity on all colors for an hour, at 10AM only red increases to 80% (factory settings), at 11AM it gets 80% on all colors, except green which is 50% (factory settings), at 6PM it goes down to around 20% on all except red which is still 80% (factory settings) for 2 hours, and then from 8PM to 11PM all colors on 8%.
I have CO2 bottle injection and try to keep concertation of 25-30 - I measure this this using electronic PH meter and a KH test. What keeps failing sometimes is my solenoid valve switch timer, which seems to reset its settings on each power failure. This happens once on two weeks or something. I am on my way to get analogue one. The CO2 injection starts with the low intensity lighting 2 hours (9AM) before the actual strong light period (11PM), where the concentration of CO2 measuring the PH is around 1PH drop ~30ppm CO2 and stable at that concentration over all the strong light period. The injection is turned off 1 hour before the intensity light period (5PM).
Doing around 50% water changes on Sundays.
Having a large life stock of around 60 small fish. I realized I feed too much but I doubt this is adding a lot to my EI dosing. Still, I decided to switch to feeding once per 2 days, for sake of fish health.

My problems till now:

any carpet or red plant will not survive in this tank. Tried with two types, which should be perfect on this setup, but they are or dissolved or really poor looking. Also I have two types of moss which looks awful for some reason.
All fast growers look good overall and not demanding plants look okay, but not perfect.
I had to move my tank to a new place and replant it. Its been around two months now, seems stabilized but I see a lot of green/brown dot algae over the scape and before each water change and cleaning on the glass.

My guess is instable / incorrect CO2 dosing and bad lightning setup. So, if someone can advice me at least on the lightning and its density periods and settings, I would solve the CO2 issue with time for sure..
Any overall advice is welcomed.
Some pictures inclided.


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## oreo57 (21 Apr 2021)

Light spectrum probably had little to do with it.
A hint from terrestrials.


> It’s important to note that activating plant response using light spectrum is one component of a larger process and results are heavily dependent on many factors such as light intensity, photoperiod, growth environment, plant species, and even plant variety.



Secondly sometimes no matter how hard you try some plants just don't err cooperate.
If your CO2 levels and fert's are fine one could up your light intensity slowly.
Just general tips.
To be honest your tank looks pretty good.
One thing w/ carpeting plants, you may want to redirect some flow over the substrate

Consider this as a discussion starter not a cure.


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## ceg4048 (21 Apr 2021)

Flukeworld said:


> With modern LED lightning where you can change the intensity of each light color what is the "recommended" periods and settings?


The recommendation for ANY kind of lighting is to avoid excessive intensity by limiting the intensity to a PAR value of approximately 30-40 micromoles as measured at the substrate. You should use any color combination that you consider aesthetically pleasing and it should have nothing to do with what manufacturers settings or recommendation.
The problem in this hobby is that few people have a PAR meter, so it's impossible to determine what the light intensity actually is. The human visual cortex is relatively insensitive to both blue and red so we cannot visually determine how much is too much.
This problem is exacerbated by the fact that these manufacturers refuse to actually provide any PAR data with their lighting units.

To make things worse, no one actually can tell with any level of certainty, whether their CO2 is good or not good.
The only way we can tell unfortunately, is if the plants fail or succeed.
Carpet plants are the most sensitive to CO2 shortfall primarily because in their habitat they are rarely completely submersed, normally having access to atmospheric CO2. So if they are planted at the bottom of the tank we need to ensure that the distribution of CO2 enriched water can make it to their location.

I believe this is where you need to focus. Adding more light just makes their situation that much more dire. You can simplify the lighting schedule by ramping the color combination of your preference linearly, or you can just use what you have now if it pleases you. Playing with colors will not really make any difference.

The GSA depicted in photo #2 is already telling you that there is insufficient CO2 for that lighting level at the substrate.
I have no idea whether your Fluval 407 is man enough for the job. You may have plenty of flow energy from your filter but that energy needs to be distributed more equitably to the substrate. There are plenty of threads discussing flow/distribution.

Cheers,


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## Flukeworld (21 Apr 2021)

Thank you, oreo57, Clive!
So we get back to CO2 issues.. May be first I need to fix this completely before going into more complicated "which-light-color-when-for-how-long". Still I am not sure can I have like 12 hours of light - for example 3 hours very low light (5-10%) in the morning, so I can enjoy the tank, then 6 hours full light and then again 3 hours low light. Could this harm or not?
As for the CO2 distribution from flow perspective - I always were in believe (check the attached pic) such placement of a filter output (ignore its internal) should make the circulation good enough. I made this picture as an example of how it is good to place your filter for local facebook group here. But now, after reading what you have posted, which completely makes sense - is the CO2 gone until the water goes down? I see the flow is moving trough the bottom of the tank, but how the dissolved CO2 is not reaching those plants at the bottom then? Is it consumed before reaching them? Is it just going up and evaporates? If this is true, then I have to completely rethink my filter output placement.. 
Other idea just came to my mind - my PH tester is water prof, so I can just put it next to the carpet plants and measure the PH - would this clear the assumption there is a CO2 issue with it if it shows the needed PH drop? What do you think? I am going to do that tomorrow


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## zozo (22 Apr 2021)

Clive and Oreo pretty much sum it up, you even could have 18 hours of a light cycle if you wish.  With the correct plant choices even in low tech with extremely low turnover, it ain't necessarily much of an issue regarding algae growth. I have a small shallow low tech tank in the garden that receives full blast sunshine and daylight all day long for up to 18 hours in the summer. But it contains fast-growing true aquatic plants and some floaters that can easily coop with this and it never has any algae issues, not even GSA on the glass. Till now I never managed to grow the same plants this fast indoors under artificial light not even with CO². Most likely due to the lack of light intensity my artificial light source could produce.

Next to it, I have an indoor low tech tank that receives indirect daylight from a Skylight directly above it for the exact same period but it is less in intensity. And it contains relatively slow-growing plants such as Anubias and Crypts. And in its 5 years, it never had an algae-free day in its life. It grows GSA on the Anubias leaves and on the glass, BBA on the hardscape and occasionally I have to manually remove hair algae.  In this case, there is too much light intensity in relation to the type of plant and how they utilize light and nutrients in relation to their growth speed. This is a tank that definitively could use CO² injection to make these plants utilize it all and get healthier and grow a tad faster. But then definitively the CO² should be distributed accordingly across the tank.

If your filter isn't up to the task then an in-tank powerhead might help to create the extra needed flow around the tank.

You do not mention the type of diffuser you use... Anyway in my personal experience for the few years I did high tech aquarium I noticed the inline diffuser compared to the in-tank diffusers, the inline doing the most sufficient job with saturating the water with CO² before it reaches the tank. The flow speed in the tube makes the water take up the CO² more sufficiently. The in-tank diffusers spoil a lot more CO² into the atmosphere by creating too large bubbles that do not fully dissolve.

To find dead spots in your tank you could weigh down a drop checker and place it a cm above the substrate and visually monitor what is going on there. This way you can place several or move one around to a different spot the next day. Without any visual input, it's guessing the obvious. And if all seems to be in order, you might want to try a different plant sp. that does better with the parameters you can provide.

For example, I was never ever able to grow Staurogyne repens whatever I tried it always died on me for some mysterious reasons. And everybody else is telling me it's an easy plant to grow. Unfortunately not for me, no matter how much CO² I drop on its roof.


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## ceg4048 (22 Apr 2021)

Flukeworld said:


> So we get back to CO2 issues.. May be first I need to fix this completely before going into more complicated "which-light-color-when-for-how-long". Still I am not sure can I have like 12 hours of light - for example 3 hours very low light (5-10%) in the morning, so I can enjoy the tank, then 6 hours full light and then again 3 hours low light. Could this harm or not?


Hi mate,
             As marcel mentions, it is not duration that damages plants, but it is _intensity _that does the damage. Under unrreasonable intensity duration has the effect of exacerbating the damage. So it's entirely possible to have 12 hours of light if the intensity is moderated such that it does not create a demand for CO2 that goes unsatisfied. the 5-10% in the morning seems perfectly fine to me and the three hours of low light at the end seems also fine. The damage may be occurring to that particular plant during the 6 hours of higher intensity. Slow growing plants such as this normally lives in shaded areas so they easily suffer "sunburn" under higher intensities. It may require more time for them to develop the necessary pigments to defend themselves.


Flukeworld said:


> But now, after reading what you have posted, which completely makes sense - is the CO2 gone until the water goes down? I see the flow is moving trough the bottom of the tank, but how the dissolved CO2 is not reaching those plants at the bottom then? Is it consumed before reaching them? Is it just going up and evaporates? If this is true, then I have to completely rethink my filter output placement..


Well, you'll be disappointed to learn that approximately 90% of the gas we inject never actually makes it to the plant beds. The gas quickly escapes to the top almost immediately, just like in fizzy drinks. Once the CO2 reaches the plant leaves the molecules have to be captured by an enzyme called Rubisco, which is a very inefficient enzyme. So there are a lot of things working against the uptake of the gas. Light, however, has no difficulty passing through the water and is only attenuated by the inverse-square law. 
Gases diffuse 10,000 times slower in water than they do in air, so it's critical that we get the water containing the gas down to the bottom as quickly as possible. This is why I prefer to send the filter outflow across the short dimension of the tank rather than the long dimension as you are showing. Even so, the majority of your plants are not having any difficulty, so I don't see any need to change your distribution method. It might be simpler to live with a slower growth rate by slightly reducing the intensity of those 6 hours of light. 


Flukeworld said:


> my PH tester is water prof, so I can just put it next to the carpet plants and measure the PH - would this clear the assumption there is a CO2 issue with it if it shows the needed PH drop?


Yes, observing the pH drop from lights on to gas on is a great way of determining how the gas is behaving. Take readings every 30 minutes or so and record the data. That way you can compare the results to data gathered after making any changes.

Cheers,


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## Flukeworld (23 Apr 2021)

Hi Marcel,


zozo said:


> You do not mention the type of diffuser you use...


I use JBP inline diffuser. Seems doing okay and does not affect the flow at all. Previously I was using stepper stairs or whatever its called and I can tell it utilizes the CO2 better. On other hand its too bug and in my view inconsistent with what I am trying to achieve more "nature" view. I have hidden everything possible. So, the inline diffuser is the better choice for me, I just loose more CO2 but its cheap anyway. Kinda works for me 

Hi Clive,


ceg4048 said:


> Take readings every 30 minutes or so and record the data. That way you can compare the results to data gathered after making any changes.


I have been doing this exercise for pretty long time. So I have 1 to 1.1 PH drop before the intensive period and seems stable on hourly based measurements. What bugs me is


ceg4048 said:


> The GSA depicted in photo #2 is already telling you that there is insufficient CO2 for that lighting level at the substrate.


So, I tried measuring the PH around the tank, seems there are spots with PH6.8, but at the end of the jet of the filter output (the opposite site of the tank) PH is the highest 6.7. I am doing those measurements with Aspera Instruments PH20 tester, seems one of the best ones believing on web reviews. Cost me double to get as its not distributed in Europe.
On topic, I did measure the PH at the bottom of the tank, behind the stone, etc. I was not expecting a difference and yes my PH is the same there. So, the only things in my mind I could do:

Lower the light intensity of the 6 hours bright / strongest light period.
Increase CO2 input.
I cant go more on CO2, as I am afraid for my life stock. In my calculations I have 30ppm of CO2. I started from 20 going up trying to solve "CO2 is most common issue". You can check the spreadsheet picture describing my obsession of improving things 

In the end, is it possible to have the same PH next to the carpet plant and still it to be CO2 deprived?

I have also attached image of how the same plant survived for moths and spread a bit  - it somehow reached the moss at the filter output pipe on tank surface. This is how I keep trying propagate it on the bottom without loosing it. It is always under water level, so it should not get CO2 atmosphere. The only things I can come to is - it is getting more light + the fish stock, especially livebearers cant touch it. But still, I have never seen them directly eat it and in the same light the one at the top of the tank is green and flourishing but the one at the bottom is yellowish.

On the light periods question I believe I got my answer. Overall, it will be try and observe game, rather than get your exact answer 5.. but still I got what I missed that not only hours count and you cant just rely on "manufacturer" did what its best for that light source. The main outcome: "I need to play more with intensity before going up on hours."

So thank you!
Regards,
Fluke


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## Zeus. (24 Apr 2021)

Think if your after a carpet you will need to increase the tank turnover a bit IMO, Fluval 407 output is 1500 LPH which should cover the x10 rule in theory however the pic you posted



doesn't convince me that it getting enough, as if it was there would not be a carpet full of detritus and algae as in your pic, when was the last time you cleaned the detritus from the carpet? I managed to keep a carpet going for 3 years under 50cm of water and the flow was always excellent with the CO2 bubbles hitting the carpet on the opposite side of tank, even manged to grow MC in a thick carpet of Eleocharis acicularis 'mini' and Lilaeopsis brasiliensis 'micro swords' 



Regular turkey blasting the carpet regular and flow well beyond x10 and good pH drop (DC was yellow) Full pH drop by lights on and stable (within 0.1pH drift from lights on till CO2 off) photoperiod 6hrs


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## ceg4048 (24 Apr 2021)

Yeah, as Zeus mentions you may want to supplement the flow, especially since you are moving the water on the long axis of the tank. Try adding a Koralia or similar to boost the energy heading to the opposite side of the tank. If you are at the limit of how much gas the fish can take but still suffer issues then the flow/distribution and/or light need to be addressed.

Cheers,


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## Flukeworld (11 Dec 2021)

I know its been a while, but I keep experimenting and I am here again with different question 
The tweaking of  light intensity gave its results. I no longer get algae on tank glass, no any on fast growing plants and much less on slow growing ones. But few months ago I also upgraded the tank with spray bars which helped on this for sure.
 I still don't have a carpet plant, I almost gave up on this. But a week ago I had a gift of some short plants I can put on bottom in the front.
I got them for a week, for now they seem fine, but I am not impressed of "the flow" around them. They collect a lot of debris and I believe its my flow rate.  My Fluval 407 is not strong enough for the height and volume of the tank. Last week I almost emptied it from media to see if it would make any difference. It does, but still I believe not enough. I even had ideas on removing of the inline CO2 diffuser, which for sure burdens the flow somewhat as its diameter is tinnier than tubes. I am still considering keeping it, as changing the way I dissolve CO2 for sure would bring some other problems.

So, I am on enhancing my flow using Koralia Nano 1600l/h. I am thinking on this for long time. May be after Clive mentioned it here. My local shop had those out of stock but now they have them! But I am not sure if I get one, how do I position it, to supplement the flow / help "carpet" get enough flow, long stem plants get some love in their low part (I have a lot of decaying leaves there). So if you could give some hints, I am all out to buy one of those Koralia pumps.
Here some pics to ease the process (excuse my great Microsoft paint skills).
This is the current spray bar setup:








And here is what I am wondering about as which would be the best position for Koralia:




So basically my reasoning:
1. Would be best to help carpet plants.
2. May be would help get some flow at the bottom of the tank, high stems would get some flow in their low part. May be also the carpet will feel the movement, not sure, need to experiment.
3. Well, flow for the most stagnant part - back of my tank.
4. Positioned to face front glass, so it compliments the spray bars direction increasing their flow somewhat.

Any ideas?


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## Zeus. (11 Dec 2021)

I would place them under the spray bar as their output would then be working with the spray bars output.


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## Flukeworld (24 Jan 2022)

What I did instead is to clear my pipes, remove 80% of media from the canister. I kept just around 1-2 centimeters in each basket where those were top full as previously I have added some additional media to fill them up. All of this increased the flow a lot. Now I can see the leaves of plants in the bottom front and also in the back to gently move. This, including other corrections in fertilization approach seems helped to get overall tank plant health up. Picture describes itself.


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## Flukeworld (20 Oct 2022)

Almost 9 months passed from this upgrade, so  I resurrect a bit this thread.

Overall, the things solved after the spray bar upgrade, optimizing and increasing the flow by emptying 80% of the media from the filter, touch a bit on the CO2 diffusion and gassing schedule to maximize the stable 30ppm CO2. There also many other upgrades such as making my own ferts from salts and dosing full EI. I still suffer some algae here and there, but overall the tank looks good and I have amazing growth on everything. Well almost. I never managed to grow mosses well in this tank, as you can see on the pictures they are really suffering. One of the things I assume partially the stunt was caused by higher temperatures in the summer - close to 27-28 degrees.

Some pics from 15th of October:






 




Here christmas moss:


 



Meanwhile in the summer to keep my tank temperature lower I removed the glass cover. I still keep it removed as I believe this increased the PAR of my lightning. I always had some suspicion its not enough at the bottom. I would never again get a tank over 45 centimeters.

On the other hand I have assumed that water evaporating from an uncovered tank and a spray bar with CO2 inline diffuser do not work well. Around forth day after the water change its level drops with around 1-1,5 centimeters and I see the drop-checker is not yellowing as on the first day after topping the water. I think this is causing the effect of "unstable CO2". I see sometimes the front glass of the tank change with green tint algae just for few hours on forth or fifth day after the water change.  I still have no solution for this rather than toping of the water midweek which I find very annoying. My spray bar is not exposed after evaporation, it is still 3-4 centimeters under water level but seems the gas is reaching faster the surface and dissolve less.

I have an idea but I am not sure if it could work and I am a bit afraid to try as it could risk the fish health:
So, my question is if a tank has a variance of CO2 enrichment for example from 50ppm on the start of the week and 30ppm at the end just before the water change while in light period, will it also have the effect of "unstable CO2 levels" or if you have ppm over 30 its fine even if there is variety but only over the 30ppm value?


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## Yugang (21 Oct 2022)

Flukeworld said:


> On the other hand I have assumed that water evaporating from an uncovered tank and a spray bar with CO2 inline diffuser do not work well. Around forth day after the water change its level drops with around 1-1,5 centimeters and I see the drop-checker is not yellowing as on the first day after topping the water.


Your observation is correct. The CO2 level at which the tank stabilises during the day is very much dependent on the surface agitation and therefore how the spray bar is positioned near the surface. I checked pH profiles for months, and was surprised how important water level is when I aimed at a 0.1 pH stability over time. It for this reason that I top up water daily, and keep my water level stable within a few mm.



Flukeworld said:


> So, my question is if a tank has a variance of CO2 enrichment for example from 50ppm on the start of the week and 30ppm at the end just before the water change while in light period, will it also have the effect of "unstable CO2 levels" or if you have ppm over 30 its fine even if there is variety but only over the 30ppm value?


Fluctuations between 30 and 50 ppm (assuming that you have a correct and accurate measurement) are not optimal. As a rule of thumb, try to aim to stabilise pH within 0.1, which corresponds to 25% CO2 ppm variation maximum. With larger variations than that it may work, but more prone to issues with certain plants or BBA.

I love your tank, so would add "don't fix it if it ain't broken"


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## Flukeworld (21 Oct 2022)

Yugang said:


> I love your tank, so would add "don't fix it if it ain't broken"


Thank you!


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