# 20g lighting



## dabrybry (Jun 27, 2010)

Hey there fellow apc'ers! So long story short, I'm getting back into the hobby, got a 20g long, but the only light I have left is a 30" t5ho quad fixture. Obviously overkill for the tank. How would you handle that? I'm thinking suspending it higher may be the best option, but I'm not too sure how high to go, I need enough penetration to grow a nice thick marsilea minuta carpet without burning my stems. Any thoughts?

Thanks in advance for any comments/suggestions!

-Bryan


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## old 97 (Jul 25, 2011)

Seems like a substantial mismatch with no easy solution.

My first thought is that, by the time you hoist the lights high enough your own reflection is all you will ever see in the pane. I can't stand light spill; so suggestions are further limited.

If you cannot simply remove a couple bulbs within the existing fixture,a cheap and effective hack would be a new ballast.

2 X T5HO or perhaps 4 X T5*N*O

Examine the diagram on the back of the ballast a two bulb schematic may be illustrated.

What happens if you untwist a single bulb?


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## niko (Jan 28, 2004)

Yes, it would be best if you remove a bulb or two AND suspend the fixture as high as your eyes can stand it.

But you can go another route if you are brave enough to leave aside the common internet "knowledge" that we all freely share; Believe it or not you can actually use the fixture the way it is and not suspend it too high either. But you have to make sure that your tank is extremely clean. That means getting rid of trash that you cannot see. You clean the tank by doing frequent small water changes (10% daily) AND making sure that your biofilter is working well (no clogging, no bypass). The daily water changes are not something you will have to do forever - just until everything stabilizes. 

If the fixture that you have is one of the run of the mill "amazing" things made to make more profit than PAR then the useful light that will hit your plants is actually less than you think. It looks bright to you but the plants see it differently. This is a good thing in your case because no matter how you twist it you do have a lot of light and the only way you will stay on top of the game is by maintaining the tank pristinely clean and providing enough nutrients. The best option is to have a rich substrate and as little ferts in the water as possible. But with lots of light you will have to dump some ferts in the water too. That will work, guaranteed, ONLY if your tank is exceptionally clean. If you must have more than a few small fish in the tank forget the whole idea of a clean tank.


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## Phil Edwards (Jan 22, 2004)

If you're able to have half the lights on at a time that would also be a good alternative. That's what I'm doing with my 6x bulb fixture; half on for 5 hours and the other half on for 5 hours. That allows me to use different bulb combos to give the plant different spectra without overloading the tank with light.


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## dabrybry (Jun 27, 2010)

@old 97 - It would appear that I can untwist one or even multiple bulbs while the others remain lit. This could be a decent temporary solution until I can come up with something better/replace the fixture. 

@niko - I don't really have a problem with daily 10% water changes. There's right around ~15 gallons in there, so I could definitely handle 1.5 gallons a day. It's a coralife fixture, which I'm afraid may fall into the profit over par category : /. The substrate right now is DIY mineralized topsoil. So that should be providing a pretty solid base of nutrients, and I have tons of dry ferts left over to add in as well. Think I should gas the crap out of it too? As for the fish, I just filled the tank last night, so it won't be having any fauna until I'm reasonably satisfied with the plant/water health first. More than likely ~1-2 months.

@Phil - I think I kind of like your idea the best honestly. The bulb set up right now is 10k 10k 6k colormax. It would be nice to switch one of the 10k's out for another 6k, maybe even an actinic?


Thanks for all the replies guys . Really appreciate the help


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## DanielG (Feb 5, 2013)

Don't lose hope. I have a quad T5HO over a 20g tall. I battled algae for a while but seemed to have decimated it's existence by doing once a week 30-40% water changes, and running nutrients pretty lean (Dosing I.E.). My external canister filter is cleaned along with the WC as well as a light surface skimming of my substrate if I see anything that needs to be cleaned.

When I feed frozen blood worms, I only drop enough that gets picked off before it hits the substrate. If any hits the substrate i'll typically leave it for the dwarf frog to get.

My fixture is the Aquaticlife x4 t5ho with x3 6,500k and x1 acticinic sitting at normal height above the tank (3-3.5"). My compressed Co2 is running at about 2.5-3 bbps.


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## TropTrea (Jan 10, 2014)

If it is 4 bulb system then there are probably two ballasts inside the system. You could disassemble it and disconnect the power from one of the ballasts. You now will be reduced your total wattage in half. 

While this still may be a bit to powerful you also have the option of running one of your light bulbs as a 420nm Atinic bulbs. These bulbs produce about 1/4 of the PAR as a full spectrum bulb and most of that light is on the edge of the Ultra Violet region. I had run one these on a large planted tank years ago and it did not harm the plants , but also created some florescence that I never thought existed in fresh water fish.


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## Phil Edwards (Jan 22, 2004)

I wouldn't use an actinic as it's not really necessary. 6500-10,000K CRI range is the best for plant growth and viewing. If you want to supplement other bulbs for color or to hit specific spectra more than others, then go for it. I'd recommend choosing either 6500 or 10,0000K and using those bulbs for your typical viewing color and use one or two of the others for specific spectrum bulbs. For example, I'm using the same fixtures DanielG's using over my big tank and have 3x 6500K and 1x 680nm "Roseate", all Aquatic Life bulbs, per fixture. That works well and gives me the look and growth I want.

The other tank is getting 3x 6500K and 3x 10,000K at different times of day. I chose this configuration to provide a wider array of spectra in hopes that it would help stimulate colors and provide a wider array of light for the different photosynthetic pigments to capture. When all the lights are on together the combination is quite pleasing to my eye too. 

Ferts- If you've got soil in there the only things I could recommend dosing are K, Ca, and Mg. Don't go crazy with them either. Give them a half recommended dose unless the plants start showing signs of deficiency.


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## dabrybry (Jun 27, 2010)

I want to switch that actinic out. For some reason or another though, 30'' t5 bulbs are a pain in the #*$ to get a hold of. Only been able to find the length+spectrum I need from a few places online, and they've arrived shattered in the box from shipping twice in a row now heh. Fortunately they've been great about quick communication and replacing them, the trick is just going to be getting one intact.

I've suspended the light ~12'' over the water, and have each set on a timer now so there is only 2 bulbs on at a time. 8 hours total. My c02 setup should be finished soon, so I'll feel more confident about this set up once that is complete. Hopefully I'll be ok with all of that going on.

As to the ferts, this is my first time using the DIY mineralized topsoil thing. I have K dry fertilizer, and CSM+B. Think I should just follow IE method minus a little with those? I was kind of holding off ferts till c02 was on the tank.

Here's is a pic of the tank directly after filling it last week.


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## TropTrea (Jan 10, 2014)

From my old memory on 20 low planted thanks I had I only ran a pair of 24" Standard T-12 lights with great success. However with your set up having the lights high above the tank you need to at least double that wattage. So with your set up you will probably on the high side but still should be workable. Worst case situation would be raising the lights even higher and adjusting the timing of your lights.


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## Phil Edwards (Jan 22, 2004)

I would go ahead and add the K and traces as per EI, you should be fine with those. Get that CO2 going as soon as possible for best results.


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## dabrybry (Jun 27, 2010)

Will do. C02 arrives Monday. Everything seems to be going well so far, except for the blyxa japonica melting a little at the tips. Hopefully, the ferts and c02 will help there as well. 

Thanks for the advice all


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