# Low Light T8 Lighting for 75 Gallon



## jrl2112 (Jun 24, 2011)

I have a standard size 75 gallon planted with several Anubias nana and Java Fern but not heavily planted right now and no co2. I have a single strip aquarium light with a t8 6500k and one of the chrome double t8 light strips with 6500k bulbs that a few people seem to like from Home Depot. I have a tan pfs substrate that reflects some light from the bottom as well. I get the nice green algae coating on rocks and spots of it on the glass when using one t8 bulb for 5 hrs a day with no plants. I went to the three bulb set up with plants leaving them on about 6 hrs a day. I am noticing a slight increase in the green algae. I change about 30 to 50 percent of the water once every week to two weeks. My nitrates are 10ppm and no amonia or nitrites showing on my samples. I want to find a balance to get the plants to grow at a normal pace but am concerned that the anubias leaves will start getting alage as well. Would anyone recommend using just two t8 6500k bulbs to keep these particular plants thriving and protect against algae on the leaves or is that amount of light just too low?


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## wet-handed (Jan 8, 2012)

riccia moss might help soak up extra nutrients dont know if that will help thogh gotta starve out the algea


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## Hoppy (Dec 24, 2005)

wet-handed said:


> riccia moss might help soak up extra nutrients dont know if that will help thogh gotta starve out the algea


It is impossible to starve out the algae. Long after the nutrient concentration is so low that the plants all stop growing, any algae in the tank will be thriving and well fed.

Just the HD chromed shop light should give you all the light you need for the plants you have. If you find that the front or back of the tank is too dark, adding the strip light spaced several inches from the shop light should help. Put it real close to the shop light and you may have too much light to avoid algae problems.


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## BBradbury (Nov 8, 2010)

*Low Light, Low Tech Tanks*



jrl2112 said:


> I have a standard size 75 gallon planted with several Anubias nana and Java Fern but not heavily planted right now and no co2. I have a single strip aquarium light with a t8 6500k and one of the chrome double t8 light strips with 6500k bulbs that a few people seem to like from Home Depot. I have a tan pfs substrate that reflects some light from the bottom as well. I get the nice green algae coating on rocks and spots of it on the glass when using one t8 bulb for 5 hrs a day with no plants. I went to the three bulb set up with plants leaving them on about 6 hrs a day. I am noticing a slight increase in the green algae. I change about 30 to 50 percent of the water once every week to two weeks. My nitrates are 10ppm and no amonia or nitrites showing on my samples. I want to find a balance to get the plants to grow at a normal pace but am concerned that the anubias leaves will start getting alage as well. Would anyone recommend using just two t8 6500k bulbs to keep these particular plants thriving and protect against algae on the leaves or is that amount of light just too low?


Hello j...

In addition to the large, weekly water changes, I change 50 to 70 percent, and I have the Nerite snails to take care of the algae and float fast growing stems to use up the phosphates and nitrates in the water. I particularly like Water wisteria, Water sprite and Pennywort. These get the bulk of their nutrients from the water and really thrive in water that's a little higher in nitrates. My fish are fine in nitrate levels as high as 40 ppm, but that's the result of having very heavily stocked tanks.

I have larger tanks and use the GE 6500 K aquarium plant bulbs from the local hardware store. I wait until they run a sale on a three pack for around $15.00 to $20.00 for the 48 inch T8s or T12s. My Java fern and Anubias coffeefolia plants grow pretty well in the shaded areas of the tanks.

Get some Nerite snails from the LFS and float some stems and after a few weeks, you'll notice a difference in the algae.

B


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## jrl2112 (Jun 24, 2011)

Thanks for the comments. I am going to run the one double t8 light strip only for now. I do have a little frogsbit and a few snails may help as well. Nothing is real bad now but it is getting greener and my rocks are getting more covered so I just want to know I can control it now rather than it getting out of hand and trying to figure it out.


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## demonr6 (Mar 14, 2011)

I ran into some financial issues that have pushed back my light purchase for my 20L and after a few weeks of winging it using desk lamps with CFL's I broke down and bought a shop light at Lowe's for $13 and threw in some GE 6500k T8's. In the week since I can tell you it has been an amazing transformation. The tank already gets some light sitting next to a window, it is frosted glass but the 2 T8's have helped the plants immensely. I still plan on getting the Catalina light fixture but for now this does just fine in my low tech setup. 

I keep the light about 5 inches from the water line giving it a total of 14 inches to the sub and I have zero algae issues except for some random stuff that is not worth mentioning. None of the bad stuff and a little bit is not bad for the tank necessarily I think. The snails and shrimp all spend time munching on it. You won't be disappointed though. I know it is not the ideal setup but when you are faced with budget issues you have to make due sometimes.


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## BBradbury (Nov 8, 2010)

*Your Lighting Question*



jrl2112 said:


> I have a standard size 75 gallon planted with several Anubias nana and Java Fern but not heavily planted right now and no co2. I have a single strip aquarium light with a t8 6500k and one of the chrome double t8 light strips with 6500k bulbs that a few people seem to like from Home Depot. I have a tan pfs substrate that reflects some light from the bottom as well. I get the nice green algae coating on rocks and spots of it on the glass when using one t8 bulb for 5 hrs a day with no plants. I went to the three bulb set up with plants leaving them on about 6 hrs a day. I am noticing a slight increase in the green algae. I change about 30 to 50 percent of the water once every week to two weeks. My nitrates are 10ppm and no amonia or nitrites showing on my samples. I want to find a balance to get the plants to grow at a normal pace but am concerned that the anubias leaves will start getting alage as well. Would anyone recommend using just two t8 6500k bulbs to keep these particular plants thriving and protect against algae on the leaves or is that amount of light just too low?


Hello jrl...

Algae grows in water that's higher in phosphates and nitrates. So, to keep algae under control, just do large water changes of at least half the tank volume every week. This will stabilize the water chemistry and keep the water nutrients to a minimum. 

An added benefit of an aggressive water change routine is, you can put the test kit away, because there's no way for pollutants like ammonia and nitrites to build up before the next large water change.

The 6500 K bulbs are closest to natural daylight at 5500 K, so it's best to use those. Lighting is pretty simple, just add or subtract bulbs according to your plant's requirements. I just stick relatively close to this: low light plants need upwards of 1 watt per gallon of tank volume, moderate light plants 2 watts and strong light plants 3 watts and bright light plants, 4 plus. Just stay with the 6500 Ks.

Aquatic plants are tropical and used to long hours of daylight, so I keep my lights on timers set for 12 hours on and 12 off. This seems to work the best.

Just a couple of thoughts to consider or not. Above everything else, have fun!

B


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## Daximus (Oct 19, 2011)

How many hours a day are you running the shop lights? I have a pair on my 90, lately I've been having to step back to around 8 hours a day with my main lights, and I have Co2. Sure, 12 hours of maximum sunlight is great, but in reality I doubt many plants ever get that much. The sun rises and sets, during those times plants are likely shaded by other plants and stuff. Plus, they are underwater, lol. What I have started doing was to run a single set (or bulb in your case) for 10 or 12 hours a day, then have my other pair of bulbs kick on for 6 or 8 hours in the middle, to simulate a high noon scenario. 

As Hoppy stated, trying to starve out algae by adding more plants can be a game of diminishing results. Plus, that's just more competition for your other plants that are doing well.

Even with my low lights and Co2 injection some algae happens. Do you have any Ottos? A pair of them can be real handy keeping small algae outbreaks under control.


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## jrl2112 (Jun 24, 2011)

Hey Daximus, I got the shop light after reading what you said about it. I am not crazy about the look but it seems like its pretty good for a decent price. I had been running these about 5 to 6 hrs a day. The concern was that I felt like at least my nitrates were not very high and even with one 6500k bulb for 5 hrs I got alage so when I started running 3 and added plants it increased. I am not stocked yet with my fish either except for about 12 guppies that I will be probably be giving to someone else so no algae eaters right now. The algae will be really good for the fish but my concern was it would start getting to the plants. It's just the green alage that seems to get on rocks and glass so maybe its all good I just want to understand it and be able to have some control so that it never takes over and then not know why or how to fix it. Based on everyones input and reading I guess the facts never change. It appears that there are excess nutrients in the water either from water coming from the tap (though I can't tell that based on the water quality report) or by sometimes waiting for 2 weeks to do a water change and levels building up. So I will stick with consistent weekly water changes as well as just running two lights for 6 hrs a day for these low light plants for now and monitor the effect on the plants and alagae. From there I may be able to change the light running 1 for part of the day and 3 for the rest to see if it has positive effects on the plants but still keeping algae in control. At some point I am going to introduce algae eaters and/or snails as well. This has been a great place to learn and get information and everyones input is greatly appreciated.


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## Daximus (Oct 19, 2011)

What!? You don't like diamond plate, blasphemy, lol. 

How long has this tank been up and running? Just curious. 

Well, on my 90, with two of those lights, before I got Co2...I ran one light for like 10 hours a day and had the other one kick on for about 6 hours in the middle. I can't remember if 75s are not as wide, or deep as 90s...your results may vary. In the beginning I had a ton of stem plants, those guys suck stuff out of the water pretty good, so that probably helped me avoid some algae. 

A bit later I increased light to 8 hours...then I got a smidge of algae, but nothing major. Without dosing and getting all technical with things I think a little bit is going to happen no matter what, so I went out and picked up a pair of Ottos.

After that I ended up on Co2...so everything changed. I don't know if this helps or not, just figured I'd tell you the story. 

Every tank is different. I planted HEAVY right out the gate, and I added a bunch of fish very quickly. I personally don't believe that water changes keep algae away, I think that's rubbish. Water changes are good, but not a cure for algae. Most the stuff that algae likes, your plants like too...finding that balance where your plants are out competing your algae is the goal. 

It might mean running just the singular shop light for 8 hours a day in your case. And even that might change in a few months when you have more fish and or plants. 

Sorry you don't like the diamond plate, lol. Just think, you could have spent twice as much on a T5HO and had four times the algae. :icon_mrgr


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## jrl2112 (Jun 24, 2011)

Daximus said:


> What!? You don't like diamond plate, blasphemy, lol.
> 
> How long has this tank been up and running? Just curious.
> 
> ...


 
The tank has been up for about 5 months. I believe the difference in the 90 vs a 75 is depth only with the 90 being 25 inches and the 75 at 21 inches. I guess I really should work on getting my fish and plant load established as well since whatever I figure out now could all change whith the increased bio load.


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