I was looking at my tank and noticed something that everyone notices at some point I'm sure if you have tall stem plants planted in thick bunches. The innermost leaves never get any light and while they might not die off completely, they are more susceptible to algae and other nasties. Obviously, regular pruning, etc will alleviate this, but I stepped outside this morning to have a smoke (I know horrible) and I noticed something. There are several bushes (hedges?) planted outside the apartment of differing species, etc. I noticed since their trimming a couple of weeks ago a few stems have shot out of the hedge and grabbed the light as it were. I've noticed this in my tanks too. They'll never grow all at the same speed. The new growth was differing in color from the old leaves (this is in my tanks too) Most everything about this terrestrial plant can be likened to something going on with the plants in my tanks... except one.


There are several layers of leaves on this plant inside the outermost layer which were still vibrant and green. (on the VERY inside of the hedge, there were some pockets that didn't contain any leaves, but that's true of any bush/tree) I wondered why the growth on the inside layers could receive enough light to stay vibrant, but the plants in my tanks couldn't replicate this.... then it dawned on me (literally)

MOVEMENT! The Sun MOVES (well, technically the EARTH moves, but you get the idea) The lights in my tanks sit still and provide the plants with one pointed source the entire time they're lit, whereas the sun moves. Hence, throughout the day, the hedge outside the apartment gets light from all the angles possible throughout the day, and the older growth is still lush! The leaves on the older growth are all fully formed and don't need as much light to stay healthy.

This got me thinking... not only of a way to increase the health of my plants... but also to save some money in the process

I'll explain my little "idea" in more detail later, but I wanted to at least share my little revelation here while the actual physics of the implications stewed away a bit longer so I can do a more concise writeup on the implementation of this little experiment!

I have pondered this issue also. My old 46g tank was a dutch style tank that mainly consisted of stemed plants. The way I fought this issue was by filling the whole top of the tank with some kind of lights so the light emmision angles covered the tank. Also, as you know, the stemed plants in general grow very quickly. When my tank had Co2 I had to trim the plants back at least every other day. What I soon found to help was to cut all the stemed plants literally in half(height). This allows the lower levels of the stems to get adequate lighting, not only that but the stems would grow thicker and lusher since they didnt have to provide the whole stem with nutrients.

So, What is your idea?

Check out these pics, these arnt the most recent pictures of the tank before I tore it down. But it gives you and idea

your pics are not only the perfect example of what I'm talking about (you see the shadows under only a few layers of leaves) this is the same in nature, except the sun eventually moves and gives these lower leaves at least a little bit of light. These pics change my original idea slightly, but for the better! Thanks

(by the way I like the tank. nice mix of colors. what's the plant at about 2/3 to the right? (bright red)

I know this isn't keeping anyone in gripped suspense or anything, but I'll do a proper writeup on my idea later anyway. Right now, I'm still thinking through the implementation and seeing whether or not it's actually WORTH it.

More to come.

That plant is LUDWIGIA REPENS, when I tore out those plants I counted over 200 stems. There is allot packed in a small area there, and they just kept growing

that's most likely the most red I've ever seen in that plant. good job! what fertilization did you use on that tank?

I used Rex Grigg's dry ferts and I used to do a 50% weekly H2o change. I also did diy co2, then switched to a PB setup

The Hypothesis:

Plant life, both terrestrial, and aquatic rely on several factors to maintain optimal health. Among these factors is light. Intensity, color, luminosity, all of these things are crucial. One thing we do not (cannot?) provide with common aquarium setups is to emulate the movement of the naturally occuring light source (AKA the SUN) Once all other factors involving light are addressed for optimal growth, this should be the one thing that might help further enhance the healthy growth of plants. [a side note here: I thoroughly believe this would also promote healthy behaviors in the fauna in these tanks as well]

The Test:

To create a way for a light source resembling the sun to revolve around the "horizon" created by the in-tank substrate layout.

My Plan:

[I'll draw further details on what is entailed here later]

Three rimless tanks of medium size (back sides painted to block light) set atop the stand in an equilateral triangular fashion; back corners touching the other two tanks.

One high-flow canister type filter fitted to drain and fill all three tanks. (the three tanks should be drilled to accomodate shared water levels between them with the canister split being more for water flow than individual filtration)

Heating should be done via an inline heater connected to the filtration lines.

One Co2 tank set into the stand, with an inline reactor to diffuse the gas into the three tanks. (no solenoid neccessary, as the plants in at least one tank will always be using a portion of the gas, so Ph worries should be alleviated)

a single auto-injector for fertilizers can be fitted to the sunlight-arm (discussed later) and programmed to inject 1/3 of the necessary ferts at three different time intervals 8 hours apart from each other as each tank experiences its "8am" phase. An auto feeder could be fitted alongside this to feed the fauna accordingly as well.

I personally don't believe an auto-top off for water to be a need here, as attention will need to be paid to plants (pruning etc) anyway and this issue can be dealt with then.

THE LIGHT:

One "Hemispherical" light set on an arm extending from the center of the stand, consisting of an array of smaller lights of three differing "color values" ranging from 5800K to 7000K with 6500K being the center (and largest) light. These lights should be arranged behind a curved lens that diffuses the light lengthwise so that the angle that these lights reach the tanks will emulate the wavelengths of sunlight that are present during each of the times of day.

Another arm, set facing 180degrees from the sun-light-arm should contain a small array of LED "moonlighting" with the same curved lens in front to spread the moonlight across the "horizon". For each of these three tanks, due to the angles at which the tanks are set, this should time the rise of the "moon" with the set of the "sun"

Two options exist to implement this...

A: revolve the "earth" around the "sun" (I.E. the stand spins and the lights remain stationary)
B: go old school and revolve the "sun" around the "earth" (obviously much easier than moving the weight of the tanks throughout the day)

The way to time this movement perfectly either way? What to use for a timer? What to use for a motor?

Come one... you know you've guessed it already...

It's too simple!

I'm a genius!

ok... it's not that big a deal lol. use the motor from a 24-hour analog clock (obviously a MUCH larger clock is needed to spin the stands rather than the light)

Anyway... there was more in my brain but I need to do SOME work today

your thoughts?

Im not trying to be rude one bit, but I think this is gonna be more expensive and difficult to produce than its worth.

I think, In my tank Im gonna try to combat this issue with alternating lights. I have a total of 4 bulbs(T-5HO), that I can turn on/off 2 at a time. I have these 4 bulbs spaced out evenly above the tank. What Im gonna do is run the 2 bulbs in the back for 3 hours, after that 3 hours all 4 bubls will be on, at the end of that 3 hour period the back 2 bulbs will switch off and the front 2 will remain on for an additional 3 hours.

This will give a 9 hour photoperiod, with a 3 hour max output photoperiod in the middle. The first 3 hours will be resemble the morning time, middle 3 hours will represent the noon time period where the sun is the brightest, and the last 3 hours will resemble the afternoon.


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18k on for first 6 hours
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6500k on for first 6 hours
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6500k on for last 6 hours
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Actinic on for last 6 hours
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yes, that's the normal answer, and an obvious step up from constant pointed light, but it still doesn't actually emulate the movement of light. The same shadows will still be produced from the pointed sources. I'm not saying I'd actually CREATE the thing I was talking about, although if I were more handy, and had my own garage I most certainly would. Almost everything needed I already have. In fact, I think EVERYTHING, save the clock motor lol. It was more of a pondering of how it might be done rather than a how I'm going to do it sort of thing. In fact, the tanks all sharing one filter, light and (especially) Co2 system make this setup (albeit complicated) LESS expensive than three seperate setups. But I digress, I have enough on my plate at the moment anyway. When I move into my own place though... the experiments are ON!

I think the largest benefit from this would be CO2 use. I know someone who had a "nocturnal" tank in a room with no windows. They were sort of a night owl, so they had plenty of viewing time into the wee hours of the morning. Anyway, out in the other room with windows, they had a window planter which they installed bulkheads in. They ran the two in sequence with a large pump.
Their hypothesis was that the roots from the window planter put off enough CO2 and oxygen at different times of the day/night that they could supply the other tank with the necessary gas for whatever it needed, and visaversa to a certain extent.
Supposedly it worked pretty well, and as you can imagine, the biological filtration provided by the window planter was astounding.

I believe that your statement that "the plants in at least one tank will always be using a portion of the gas" is perhaps an underestimation of their self- fertilizing power.

Id love to see this thought out and protyped.

Another thing I was thinking of was too have the light fixture rotate 90 degrees on axis. I know that with my T-5ho bulbs(with the individual reflectors) the light is very focused. You could in sense replicate the angulation of solar rays. You could a achieve this rotation quite easily, you could use a few electronic servos on a timer. There are several other ways, but I really dont want to think that deeply right now...

yeah the original thought was to do it for one tank and emulate the horizon in that fashion, but I thought... why not let one light work for three tanks and get the same effect? Those same servo motors on timers (which might actually be a lot easier to find and definitely easier for my non-engineer brain to implement) could just as easily spin the light bars 360degrees on the horizontal plain. BAH, too many possibilities!

by the way... I think I'm going to slowly start collecting the stuff to do this. I've thought it through too deeply and I'm antzy now. I really don't think it'll take as much as it sounds. I guess once I get up some stuff I'll start a journal thread about my little mini-world experiment lol.

oh my gosh, you could even do one of the tanks as a lower light tank by having the light bar raise up several inches while it's over that tank! (I'm getting too deep now lol)

LOL, I hear you. Once I start on this stuff I just keep going.

I was just thinking, I have a canopy and if I could hang(by cable wire)the light fixture from a central point in the canopy and use the servos to simply push and pull the fixture on the wire. Think of it as a motorized pendullum(sp?)

My absolute favorite lighting technique is to use a solar tube. Basically a skylight that is re-directed into a reflective pipe. I saw a reef tank lit this way, and it was striking. You can get a ton of light this way. Something you could do, would be to put one skylight from one side of the roof of the house onto one side of the tank, and then one from the other side of the house onto the other side of the tank.

Good luck getting the landlord to go along with that huh?

nono... good luck getting the upstairs neighbors to go along with that! The only light I'd get is maybe light from their TV or something, and unless they have a REALLY bright TV I don't think it'll help