Lighting Help for Tall Hexagonal Planted Tank

[be4con]

Hi

I'm looking for some advice on a lighting set-up for my tropical planted tank. I have low to medium light requirement plants, without CO2 injection (I use liquid supplementation), and I'm struggling to find a light that is small enough for the tank size, but powerful enough to deliver adequate light to the depths. The plants are growing OK, though not thriving, and the foreground plants tend to grow up rather than remaining compact.

The tank is a 68L, tall hexagonal tank, 43cm across its widest point with a 50 cm water column. I currently have a 25W LED strip light (https/www.amazon.co.uk/gp/product/B0 ... _asin_title?ie=UTF8&psc=1) that purports to output 1458 lumens. From my research, it looks like I'll need 2000-2500 for optimal plant growth.

The problem is that all the lighting I see only reaches that sort of brightness with much longer strips and I obviously don't have the tank width for that.

Does anyone have any *cough* bright ideas on how to resolve this? Would just doubling up the current light source be a solution? (though that one is now off the market so it would need to be a different but similar one). If so I was thinking of adding this one: https://www.amazon.co.uk/gp/product/B0CGRDYQLT/ref=ox_sc_saved_title_1?smid=AGFRT69ARJT4Z&th=1

Thanks in advance

 

[MaloK]

At this point, there is two questions.

1- do I like this strip ?
2- can I had a second one ?

If you respond yes to more than one of these questions there's no problem.

The fun part is you can light more the front for the lower plants and less the back for the taller ones...

 

[be4con]

Thanks, I hadn't thought of that, and it's exactly what I have done. I've also been able to vary the time further using the 2 lights, so not only do I get brighter light for the foreground, but I also get the 2nd light coming on for a shorter period so that the light is brightest during the middle of the day and lower in the morning and afternoon. Much like real life! I can't measure the brightness as I don't have a meter, but it is significantly more light in the tank now and, in theory at least, the sum of the 2 lights should give me a round 2200 lumens during the peak. Thanks for your suggestion.

 

[10 Tanks]

Hello be4. Tall tanks are a bit more challenging to light, but not impossible. The easiest way I've found is to figure on three watts of light for every gallon of tank volume. A 17 gallon tank, especially a taller one, will need roughly 50 watts of light. If you keep your bottom plants to those that require low to medium light, the plants should grow well. As for fertilizer, just feed your fish a varied diet of flakes, freeze dried and even a little frozen food, the fish will provide all the nutrients the plants need.

10

 

[be4con]

Hello be4. Tall tanks are a bit more challenging to light, but not impossible. The easiest way I've found is to figure on three watts of light for every gallon of tank volume. A 17 gallon tank, especially a taller one, will need roughly 50 watts of light. If you keep your bottom plants to those that require low to medium light, the plants should grow well. As for fertilizer, just feed your fish a varied diet of flakes, freeze dried and even a little frozen food, the fish will provide all the nutrients the plants need.

10

Thanks 10 Tanks, I think we have hit the right wattage per litre based on what you suggest and my 2 light setup - I'm at 45W and the tank is about 15 gallons. Time will tell if I need to add any more light.

 

[MaloK]

Thanks, I hadn't thought of that, and it's exactly what I have done. I've also been able to vary the time further using the 2 lights, so not only do I get brighter light for the foreground, but I also get the 2nd light coming on for a shorter period so that the light is brightest during the middle of the day and lower in the morning and afternoon. Much like real life! I can't measure the brightness as I don't have a meter, but it is significantly more light in the tank now and, in theory at least, the sum of the 2 lights should give me a round 2200 lumens during the peak. Thanks for your suggestion.

Your project looks like a lot of fun is on it's way !!! Share some pics when you get the time !

 

[be4con]

Thanks - I posted in the TOTM thread - here's a couple of pics of my work in progress plus one to show how I've set the twin lights up - it's a snug fit and the support arms don't all work because of the tank shape, but I've joined them together using bamboo kebab sticks and cable ties, which holds them secure from taking a dip, until I have something more suitable! Next step is to colonise the hardscape wall at the rear, probably with some Anubias, and then wait for my foreground plants to thrive and fill in the gaps.

 

[StevenF]

The plants are growing OK, though not thriving, and the foreground plants tend to grow up rather than remaining compact.

many plants that prefer full sun will grow unusually tall if they are shaded. Shadded light is high in blue light but deficient in red light. Full sun will have a balance of red and blue. Plants need all colors of light but many use red and blue light to regulate growth. from your link the light appears to have red and, blue, and white LEDS. If you can Try maximizing white and red and minimizing blue or turning blue off entirely. white LEDS are good at producing a lot of colors including blue but generally don't produce a lot of red.

For my tank 12VDC strip lights about 1cm wide and you cut to the desired length. I used high brightness 3000K +90 CRI (color rendering index) white and latter added 660nm red led strips. Without there'd my foreground plants were pushing 5" tall when normally they grow 1 to 2 inches. After adding a little bit of red the plants are now the desired height ( 1 to 2 inches.. I cut a 1/4 thick piece of clear acrylic plastic to fit the top and a matching 1/16" thick aluminum plate to match. I coated one side of the aluminum with clear plastic tape to insulate the strips from the aluminum and then mounted as LED strips. I have 3 square inches of aluminum for every watt of power consumption. The aluminum keeps the LEDS cool without a fan. I then added wired the strips together to a ramp timer / dimmer.which I mounted on top of the new cover. A foam gasket keeps the water out and the two parts were attached with screws. It has ben reliable and is capable of high brightness but is disable to low brightness.

 

[be4con]

many plants that prefer full sun will grow unusually tall if they are shaded. Shadded light is high in blue light but deficient in red light. Full sun will have a balance of red and blue. Plants need all colors of light but many use red and blue light to regulate growth. from your link the light appears to have red and, blue, and white LEDS. If you can Try maximizing white and red and minimizing blue or turning blue off entirely. white LEDS are good at producing a lot of colors including blue but generally don't produce a lot of red.

For my tank 12VDC strip lights about 1cm wide and you cut to the desired length. I used high brightness 3000K +90 CRI (color rendering index) white and latter added 660nm red led strips. Without there'd my foreground plants were pushing 5" tall when normally they grow 1 to 2 inches. After adding a little bit of red the plants are now the desired height ( 1 to 2 inches.. I cut a 1/4 thick piece of clear acrylic plastic to fit the top and a matching 1/16" thick aluminum plate to match. I coated one side of the aluminum with clear plastic tape to insulate the strips from the aluminum and then mounted as LED strips. I have 3 square inches of aluminum for every watt of power consumption. The aluminum keeps the LEDS cool without a fan. I then added wired the strips together to a ramp timer / dimmer.which I mounted on top of the new cover. A foam gasket keeps the water out and the two parts were attached with screws. It has ben reliable and is capable of high brightness but is disable to low brightness.

Thanks for such a detailed response, that's really helpful. I don't seem to be able to disable just the blue, but I could run the 2nd light module with only red light and see if that makes a difference.

Would you be able to share photos of the DIY LED strips in situ so I can visualise it a lot more clearly?