Is it possible to have healthy plants without algae with strong lights (high PAR)?

[Marcel G]

I would like to ask more experienced aquascapers if it is possible to have (in the long term) a tank without algae under quite a high/strong lights? Recently my friend send me a link to one of the Tropica's tanks (http://www.tropica.com/en/layouts/layout-54-%28270l%29/description.aspx), where there are quite beautiful plants and everything seems just perfect. It is stated the lights are 4x54W. On the YouTube video you can see the plants are pearling, so I would say there must be strong lights (high PAR values) - although it's just my speculation. Also on the pictures in the gallery is seems that on the rocks there is some green algae, and also the substrate layer seems to be green in color. Does anyone have possitive experiences with strong lights (let's say over 100 μmol PAR), and at the same time no algae at all? Or does anyone know how much PAR at the substrate is OK for plants to prosper (giving no room to algae)? I remember that Tom Barr measured 6-7 ADA tanks with the results of 35-55 μmol PAR at the substrate (which is quite low). Quite often I see people using high light setups, and fighting with algae. So I just want to know if someone have similar experiences with the correlation/connection of strong lights and algae.

PS: I know the lights are not the only thing that have an impact on algae (although I think the lights are among the biggest players).

 

[dutchy]

I have very good experiences with PAR values up to 75 - 80 at the substrate. This gives good growth and I'm not bothered by algae. If I use more, and I have, algae is the result. This is probably a consequence of CO2 limitation and I would have to increase the CO2 level. So how much PAR you can effectively use is more depending of the effectiveness of your CO2 setup and will to use high CO2 levels, which I don't increase more if I notice increased breathing of fish.

I like bright tanks with a lot of light, but the increased maintainance and a less forgiving system isn't worth it to me. 35 mmols is definately to dark for my taste, so I found a good average with around 75 mmol. I use 252 Watts on a 180 gallon tank to get that amount of PAR. No reflectors.

The amount of Watts is still a bad comparison because it depends a lot of other conditions like type of bulb and the use of reflectors. I can almost double the amount of PAR using reflectors.

 

[Marcel G]

Can I ask what type of lights do you use, and how high you have them above the substrate?

 

[dutchy]

4 rows of T5HO, all 6500K, 20 inch above the substrate.

 

[Marcel G]

Thank you very much dutchy for your reply!
Actually I have similar experience. Once I used 2x T5HO+reflectors just above the water surface (cca 15 inches above the substrate), which gave me about 150-200 μmol PAR (just guessing - I don't have PAR meter). At such a high light setup I was just not able to suply enough CO2 (given I was adding more than enough other nutrients: 35 mg/L NO3, 20 mg/L K, 3 mg/L PO4, 0.5 mg/L Fe + micro), so some of my plants suffered and algae were on the increase. The algae were not such a problem, but it made me not happy. Then I just raised my lights 30-40 cm above the water surface (cca 80-90 cm above the substrate level), and the algae were gone. Its true I don't have so shiny tank now, and my plants are not pearling any more, but the plants seem to be more happy (no algae). I just wanted to know if anyone else has this kind of experience, or if someone did some testing as to how much light (PAR) is safe for most plants before they begin to suffer (and algae take hold). I know that in high-light setup with EI dosing the CO2 would be probably the most limiting factor. So I just wanted to know how much light (PAR) is safe for plants let's say under 30-35 mg/L CO2 (with good water circulation). So according to dutchy 80 μmol PAR seems to be the border line. Is that right?

 

[dutchy]

Thank you very much dutchy for your reply!
So according to dutchy 80 μmol PAR seems to be the border line. Is that right?

I actually said that I have good experience with this PAR level. That's something else....

 

[Marcel G]

Sorry to disinterpret your statement. But at least this PAR level seems to be safe (at least in your setup).
I hope, someone else also shares his/her experiences.

 

[Marcel G]

I think it would be helpful if more people who have thriving plants with no algae could tell us what kind of lights they use, and how high above the substrate they have them (and if they know it, how much PAR they have at the substrate).

 

[jcgd]

I use a DIY led setup. The lights are about 40" off the substrate. My light levels are around 140-160 at the surface. The range at the substrate is anywhere from 10-70umol but I can check when I get home. I've been slowly dropping the light intensity and the more I do, the better the shape of the tank overall. My rotala all stunt with more light. I think it is co2 but I've been trying to lower the light while I up the co2. I still have full pearling after 3-4 hours of my photo period.

 

[1077]

In my expierience thus far,Yes it is possible to have healthy plant's without algae, or high light,or CO2 injection.
Growth is slower,more manageable for me.

Along with limitation's on what plant's do better than other's.
Prolly not much help but ,do I get point's for staying on topic?

 

[Marcel G]

To 1077:
I was not asking if it is possible to have healthy plants without high light or CO2 injection (that's possible for sure). I was asking if it's possible to have healthy (algae free) plants WITH/UNDER high light. That's problem for me (and also for many other people I know). If I have high PAR values (100-200 μmol PAR - at the substrate), my plants nearly automatically begin to suffer from algae. I know that ADA suggests to have HQI (MH) lamps 30-40 cm above the water column. That would give us quite low light at the substrate (despite the high output of MH lamps). Tom Barr measured the light in 6 ADA tanks as 35-55 μmol PAR. So I wonder if there is some experienced aquascaper (or anyone else) who uses high light setup (> 80-100 μmol PAR at the substrate) without any problems with algae? I suppose it would suggest using high CO2 concentration also (or strong limitation of some nutrient like PO4).

To jcgd:
I don't understand your last two sentences. Please, can you explain a little bit further what do you mean? Thanks!

 

[Gerryd]

Hi,

Yes, it is more than possible to have high light, PAR > 100 at the substrate, and have no algae.

I am currently doing it in my 220, and Tom has extremely high PAR in his 120..

 

[1077]

My apolgies,,
I was referring to your request for others who have thriving plant's and no algae to respond.
Was unclear to me that you were interested in mostly high light application.(sorry)
Agree with your assessment that many people struggle in effort's to make plant's adapt to their lighting, rather than adapting light to suit the growth of particular plant's in particular aquarium.

 

[Marcel G]

Hi,

Yes, it is more than possible to have high light, PAR > 100 at the substrate, and have no algae.

I am currently doing it in my 220, and Tom has extremely high PAR in his 120..

Hi Gerryd,
please can you tell me how is this possible?
Do you somehow limit your plants so that they don't need so much more CO2? How many CO2 do you supply? How much PAR do you actually have at the substrate? What is the key for it to be possible according to you?
Thank you beforehand for your reply.

 

[Crispino Ramos]

My apolgies,,
I was referring to your request for others who have thriving plant's and no algae to respond.
Was unclear to me that you were interested in mostly high light application.(sorry)
Agree with your assessment that many people struggle in effort's to make plant's adapt to their lighting, rather than adapting light to suit the growth of particular plant's in particular aquarium.

Smart thought 1077, intelligent, good thinking.

 

[Tom Barr]

You can use other species to partially shade less light demanding species or species that are adapted to lower light/lower CO2, not as competitive as other species.

Or place them in the corners etc.........

While it is possible and I have such tanks.......it also requires more work and effort to keep them looking nice over time.
I think simply having more patience often is the key.........ADA's tanks are lower light and grow slower than my tanks, I have 5 tanks at home and then AFA has 6-10 tanks at their store to compare to, so it's not a statistic of just 1 or 2 aquariums.
I have tanks that are up to 4-5x what the same ADA tanks have.

I do not have ALL my tanks this way, it's too much work.
Also, the plants in 2 of the tanks simply do not need more light.

The 120 gal has the most light and is full of stem plants. I try and chose slower, hard to grow species to sell.
I clean and trim this tank often, I rarely every clean the 180 Gal, but I recently added more light to that the last 3 months. About 100umol on the bottom.
The 120 has 120-150umol on the bottom, nearly 650 at the surface.

If the CO2 has an issue, I quickly get algae.
In the lower light, higher CO2 tanks with little uprooting, I virtually never have algae issues even if the CO2 is off for a day or two etc.

It's a weird thing, many people who claim to love low dosing and few water changes, love high light............... which is counter to why you would ever want high light to begin with.
Less light means less work, more patience and letting things grow in nice and slow.

Lower light= lower CO2 = lower ferts
Higher light= higher CO2= higher ferts.

You are not going to escape that relationship for demand and Liebig's law supports it.

 

[Marcel G]

To 1077 (#13):
I apologize for unclear question, and thank you very much for your answer.

 

[Marcel G]

Lower light= lower CO2 = lower ferts
Higher light= higher CO2= higher ferts.

You are not going to escape that relationship for demand and Liebig's law supports it.

Many times I have read than when we limit plants by PO4 (for example), they will not be so "hungry" for other nutrients (NPK+Fe and CO2) - in accordance with the Liebig's law. I was just wondering if it means that when I dose 0.1-0.2 mg/L PO4 (very lean dosing), the plants will not bother with high light. So when I limit them by PO4 I can use extra high light, and still they will do OK. Is that true? Such a logic seems weird to me. I think that high light forces plants to be more "hungry" (thirsty) - despite of the level of other nutrients. And even though we limit them by some nutrient (e.g. PO4), the high light will make them somehow suffer. Please, can you explain to me, what is the impact of high light on the plants, and in what circumstances it can cause them to suffer? Can I somehow compensate/attenuate extra high light (high PAR) to plants? So if I have very strong lights, is there something I can do for my plants to thrive better (is there something what would help them to withstand/endure it better)?

 

[Gerryd]

Hi Gerryd,
please can you tell me how is this possible?
Do you somehow limit your plants so that they don't need so much more CO2? How many CO2 do you supply? How much PAR do you actually have at the substrate? What is the key for it to be possible according to you?
Thank you beforehand for your reply.

Hi,

Good c02, good maintenance, and some effort

I have 90-115 umols at the substrate. If you look at my recent pictures of my 220, the java trident in the tree and the anubias minima/petite in the same tree are getting 175 umols and >. I see no algae on these plants at all.

I do NOT limit my plants in terms of nutrients. If I want slower or less growth, I will reduce the light.

 

[Tom Barr]

Many times I have read than when we limit plants by PO4 (for example), they will not be so "hungry" for other nutrients (NPK+Fe and CO2) - in accordance with the Liebig's law. I was just wondering if it means that when I dose 0.1-0.2 mg/L PO4 (very lean dosing), the plants will not bother with high light. So when I limit them by PO4 I can use extra high light, and still they will do OK. Is that true? Such a logic seems weird to me. I think that high light forces plants to be more "hungry" (thirsty) - despite of the level of other nutrients. And even though we limit them by some nutrient (e.g. PO4), the high light will make them somehow suffer. Please, can you explain to me, what is the impact of high light on the plants, and in what circumstances it can cause them to suffer? Can I somehow compensate/attenuate extra high light (high PAR) to plants? So if I have very strong lights, is there something I can do for my plants to thrive better (is there something what would help them to withstand/endure it better)?

Why have high light and put all that energy into the system, when you are not going to use it?
Low PO4 etc does not save anyone from algae.

Higher light = means more risk of algae and the intensity will be higher as well.

You are wasting excess light energy. Plant growth does not START with PO4.........it starts with light.
If you want to limit growth, start there with light.

The next step if you want to further limit growth, CO2.

Now you have a holistic method and you can limit PO4 as well, and have a much more robust and reduced risk of algae.
It's not one thing, you balance each aspect to achieve the best result.