# Light vs hight



## catweazle (Feb 8, 2010)

*Light vs height*

Hello,

New to this forum (please forgive me for my written English), but with the plan for a "NPT".

The specs will be, I think at this point:

125cm*55cm*35cm

The water height will be 30cm.

Why this specs? IMHO is 30-40cm the barrier for swampplants. With in mind that de number of plant species in a NPT is limited, this could be a good height.

This also means that the light-requierements may differs. It is more easy for the light to get in the water. Can anybody tell me if this has consequences for the amount of light above the tank? I could not find anything about this in "Ecology of the Planted Aquarium".


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## mudboots (Jun 24, 2009)

My water depth is a little more than 53 cm (23 inch tank height, minus a couple inches for substrate). I've got T5-HO fixtures, and have not had problems getting light to the Marsilea sp. in the foreground, which is pretty much at the substrate, and maybe a couple inches tall in certain areas.

My advice, if you are concerned about light penetration, is simply to make sure that your fixtures have really good individual reflectors.


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## catweazle (Feb 8, 2010)

Thx,

My concern is that I'll put to much light above it. When I look at the "rule" 2-3 watt a gallon, I think that does not say anything about height. There is a difference between 30cm height and 50 cm height. I do not want to have to much light, cause I think I have to use additives in that situation, and for this tank I don't want that. (But then again, I'm used to look at the plants and if there is reason I don't see any reason why notuse additives, but for this tank I'm planning I realy want a El Natural to prove to the Dutch forum communities that there are several methods, and not one.)

By the way, which Marsilea you keep? I'm planning to use Marsilea hirsuta. I've tried this plant in several aquariums (At this moment I have 4 tanks) and even in "difficult" light-conditions it grew. Not that fast as in my big tank, but it grew. So it could be a alternative for HC or Glosso.


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## bosmahe1 (May 14, 2005)

If you hang the lights above the aquarium, you can raise or lower them as needed. In my opinion, light height is the easiest way to adjust for algae elimination since in almost all cases, there is enough nutrients in the water to make algae thrive. I don't think algae can be minimized by minimizing nutrients so, make sure you add enough for the plants. Algae has less chance of growing on healthy plants. I would invest in slightly more light than you think you will need. Just raise it if its to much light or turn off some of the bulbs if possible.


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## dwalstad (Apr 14, 2006)

*Re: Light vs height*



catweazle said:


> The water height will be 30cm.
> 
> IMHO is 30-40cm the barrier for swamp plants. With in mind that de number of plant species in a NPT is limited, this could be a good height.
> 
> This also means that the light-requirements may differs. It is more easy for the light to get in the water. Can anybody tell me if this has consequences for the amount of light above the tank? I could not find anything about this in "Ecology of the Planted Aquarium".


I can't see how a 30 cm (about 12 inches) depth would restrict plants. Stem plants and Amazon Swordplant would grow to the surface-- right under the lights.

I would go with more light, up to 3 watts/gal. You can always move the lights up or add floating plants to cut down on the extra light.

Make sure that you give your plants a daylength of at least 12 hr (that's not in the older printings of my book). You can search this forum for "Siesta" to get more information on daylength.


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## catweazle (Feb 8, 2010)

Thanks for the replies. (And thanks for the book, I've got the 2003 version, second edition)

@bosmahe1,
In the Netherlands we are not used to open aquaria, so we do not have the possibility to play with the lights. And algea? I'm not affraid of them. I don't believe in algea-free aquaria. They are an illusion. Still I do not want to use additives in a NPT. And that won't be necessary .

@dwalstad,
I see your point. Let's say I made a wrong assumption. In the Netherlands when we buy swampplants for our little ponds we are used to putting them in zones, 30cm-40cm is the barrier, deeper only Nymphaea wil grow. But not really comparable with the Amazon or Southern Asia, ofcourse.


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## f1ea (Jul 7, 2009)

When you say 30-40 cm is the limit for swamp plants, do you mean for bog/marginal pond plants?
The kind that grow partially submerged on saturated soil and leaves above water? Maybe you want to do a El Natural Paludarium... If that is the case, then yes, 30-40 cm is more or less a limit, but if you are going to be using full aquatic plants, you can have much higher depth.

For truly aquatic plants, you can have 30-50 cm without much trouble. Just adjeust the height of your lights if you run into trouble... so the dutch don't have open tanks? well, you could be the first...  

Tot ziens!


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## mudboots (Jun 24, 2009)

catweazle said:


> Thx,
> 
> By the way, which Marsilea you keep? I'm planning to use Marsilea hirsuta. I've tried this plant in several aquariums (At this moment I have 4 tanks) and even in "difficult" light-conditions it grew. Not that fast as in my big tank, but it grew. So it could be a alternative for HC or Glosso.


The person I got it from had it posted as M. quadrifolia, but it has never been positively ID'd. I've got some emmersed in my Wetland-n-a-Box tank, but it has never put up any repro structures to let me key it out. I've also got a lot of another Marsilea that was given to me as "minuta", but again it has never been positively ID'd. It is being outcompeted by the larger Marsilea, which I'm okay with as long as something's growing well.


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## JERP (Feb 4, 2003)

The depth of the tank has little affect on the penetration of light. There are only two things that affect light effectiveness with distance from the bulb.

1. Water cleanliness. A cloudy tank blocks light very quickly over distance. If you have good filtration and no floating algae/green water, distance is not an issue.

2. Shadows. Light expands radially from the source and is easily blocked by taller plants and rocks. As a mental exercise, compare a single 200W bulb in a room, compared with 4 50W bulbs of the same kind spaced evenly throughout the room. You will have more even lighting with more bulbs, even though the wattage is the same. You see this in practice in kitchens with recessed lighting, vs a kitchen with a single light in the center.

Another item many people don't consider is the importance of keeping your tank lid clean. A glass lid gets covered in water deposits over time and deteriorates the amount light. Removing the lid solves this problem too.


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## dwalstad (Apr 14, 2006)

catweazle said:


> Let's say I made a wrong assumption. In the Netherlands when we buy swampplants for our little ponds we are used to putting them in zones, 30cm-40cm is the barrier, deeper only Nymphaea wil grow.


Attached is photo of my 55 gal tank that is 21 inches (75 cm) high. I see lots of plants doing very well in my tank-- despite the depth.

The idea that 30-40 cm is a _barrier_ for aquatic plants doesn't make sense. If you have strong light, aquatic plants will grow at much greater depths than 30 cm. I've seen _Bacopa caroliniana _growing in swamps at 100 cm depths.


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## catweazle (Feb 8, 2010)

This will be a long answer, and I'll hope I will express myself in a way you understand me.

First, I knew that joining this forum would give "problems", because there is a cultural difference.

About light. We don't think in watt overhere. We think in Lumen and Kelvin. Most of the people use fluorescent T8 (eight), some are using fluorescent T5 (still it is expensive), and some are experimenting with LED and very sparely HQi and CCFL, CDM-T or CDM-R.

The most used fluorescent bars are 3000K (yellow), 4000K (yellow white, 89 lumen), 6500K (daylight, 85 lumen) and 10000K (aquarelle). And not the commercial fluorescent bars but just Philips, Osram, Sylvania etc. which are used in the kitchen. In my NON NPT I use 3 890 (10000K) and 2 840 (4000K). I don't'know the Lumen by heart, so I can't give you all the numbers and it is depending on the brand. But above 50 lumen per liter (about 200 a gallon) is a highlight tank. Other forms are sparely used. There are people with open aquaria, but that will be mostly saltwater and maybe an Amano-tank.

When you buy an aquarium, most of the time it has an integrated "lighthood". Sometimes you will make it yourself, you only buy the glass tank. An example of a standard tank:

Tank of a friend








source:http://www.aquaforum.nl

Most of those integrated lighthoods only can contain 1 fluorescent T8 (eight). The more modern tanks can contain 2 tubes, sometimes T5. In the case of one tube the choice is very important when you look at the color spectrum of a tube.

There is still discussion about reflecting light (won't stop). Some of the aquarist make their own "lighthood" and say painting the inner of the "lighthood" with white is the best, sometimes (like I do) they use reflectors.

Heigth for planted tanks is set at 60 cm (23.6 inch) when keeping Angelfish (Pterophyllum), but the most are 50 cm (19.6 inch) or less. When you want to buy 70cm you have to order it. But the general idea (non scientific based) is that it is to much for a planted tank.

With swampplant I mean the plants which may grown submersed but also emersed. One of the definition could be those plants which are firm enough when held above water to keep straight. But Lysimachia nummularia won't match this, so it is not a good definition. The assumption I made was tha a plant like a Crypto can grow emersed and submersed. You'll not find them in deep water (by my knowledge). When you buy plants overhere for our garden ponds (a garden with a house is average 10 by 8 meter) so it are small ponds, the label will tell you plant this plant at 30-40 cm water depth. Real waterplants ofcourse are planted much deeper. Although for a normal pond (no koi) the depth will not be more than 80-100cm)

Then some explanation about my question. I want a low maintenace tank, NPT or Walstad based, to prove to the Dutch forum communities it is possible. About 40 years ago we all had a tank like that with almost no WC. But now, call it as time goes on progressive understanding, we don't believe anymore in old water. Weekly WC is the answer! Even when you are not dosing like in EI or RR.

I do believe that when you put enough in the bottom, you start with a good biomass, and the fish feeding is good, it can be done. But it will be still finding the correct balance. And I do not want a headstart with too much light. So I was wondering if a lower tank could have less light. Otherwise the light could be a problem. More light, more growth, more need for elements and CO2 and maybe that is not enough produced by natural ways.


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## catweazle (Feb 8, 2010)

In the above post the numbers for Lumen are Lumen for 1 watt.


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## f1ea (Jul 7, 2009)

When you go buy plants, make sure you get the scientific name and look for the plants on the Plantfinder feature on this forum. Or you can look in other places; just make sure that the plant is truly aquatic. Most aquatic plants can grow submersed and emersed, so still, the important thing is to know the plants you are getting are truly aquatic. With water depth, if your plant is truly aquatic, just make sure you are getting sufficient light to your plants.

As for light... temperature and lumens ratings are more useful to us than they are for plants. The important value for plants is PAR, which is kinda difficult to get, but a very simplified solution is to use WPG (ie. 30 W on a 15 Gal = 2WPG), you can use some of the 'daylight' bulbs or some of the specialized growth bulbs... it seems to not matter much for El Natural and most simple low tech tanks. A good base number is somewhere around 2 WPG. but VERY important is to decide if you're letting the tank get SOME sunlight... things change with sunlight. Your tank can be deeper and you don't have to worry about light penetrating (but sometimes its too much, and you have to be careful with everything else), you will also get the best spectrum from sunlight, and no electric bill....

There's a journal here on APC "Project 178" by Jason Baliban, he has a 70cm deep tank. Its beautiful. Has mostly low light species, but everything looks like its working nicely. So, the water height is not a big problem as long as you select the right plants and they are getting what they need. Amano also has a super tall tank, i think more than 4 feet (1.22 m).

As far as water changes... well, there's lots of people here on the El Natural forum that do very few water changes. And their tanks work and look great. Look around in this forum for people's water changing schedule, they are FAR from weekly.....

Doei :wave:

EDIT:
Just noticed you have this tank 
http://www.aquaticplantcentral.com/forumapc/aquascaping/68743-introducing-my-tank.html

Wow, Your tank is great!


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## catweazle (Feb 8, 2010)

@f1ea,

Indeed that is my "other" tank, but that one does not belong in this NPT forum.

The planned NPT tank won't get any sunlight.

Specialized growth bulbs are used in the Netherlands, but normally we go for normal fluorescent bulbs. I'll let my question for what it is. I've got an idea about the amount.

Maybe a picture of one of my other tanks is nice. This one is 60x30x30 (cm), so about 14 gallon. No soil, only sand, no addititives, no CO2.


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## f1ea (Jul 7, 2009)

Well, both your tanks look good. 
I am sure you can have a very succesful NPT. Just look around here how to set ip up... and go for it. After about a month or so, you'll have a very clean and healthy tank with basically no water changes.


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## catweazle (Feb 8, 2010)

I have patience. I put the topsoil in a flowerbox with water at 3 feb 2010. So I have 2 months to go. It's more time than I want. I cleared my fifth tank for a colleague. He had offspring from Discus so he needed a small tank to take them aside. My NPT will be combining the plants and fish from the cleared tank and the tank shown above in the attachment.

Before I cleared the tank it looked like this overtime (2 scapes):


















This tank was also non CO2, plain sand. Only it differed to filtering. I used a HMF. But that did not give the right result. Something I must blame myself, not the HMF. Just a bad execution.

I've been reading at this forum for 2 years. I've read D. Walstad's book. A book which must be read even if you do not want a NPT.

Still I "experience some cultural differences". We really do not think in WPG. Most of the more experienced aquarists look at Lumen. On one Dutch forum a member researched the outcome of T5 adapaters (the ones you use to put T5 in a T8 fixture). The outcome was put in Lumen/watt.

But then again, when you read in the States I grow mermaid's weed in one of my tanks, that must be strange. In the tank which I attached in the above post, I breed Heterandria formosa. That must be strange for you to. When you want to buy them overhere you pay € 3,00 (for the sake of simplicity say $3-$4) for one fish. When you are living in Florida you will laugh about this.


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## Tuiflies (Jan 21, 2010)

I think the depth recommendations included with plants intended for outdoor ponds are there because the only light is from the sun. Temporary shade from trees, buildings or the side of the pond and multiple days of moderate/low light during overcast skies or evening/morning sun probably all contribute to the "rating". Since ponds rarely have aquarium grade filtering systems I'd imagine water clarity is a major factor as well. Plants with higher light requirements can only get it if they're closer to the surface of the pond. I don't think it has anything to do with them being capable of emmersed growth (or being called as bog plants).


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