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Understanding my lighting

3K views 11 replies 2 participants last post by  majorwoo 
#1 · (Edited)
Hello, I have been doing freshwater tanks for years but up until a week ago I never had real plants in them. Lighting always consisted of turn it on to see the fish :)

Basic details:
Tank size: 55 gallons - 36 long, 18 deep, 24 tall
Lighting: Corallife T5 dual lamp fixture (corallife 10,000k and PowerChrome Aquaflora 39w ) (directly on top of tank)
Filter: Eheim 2217 canister
Substrate: plain old aquarium gravel + seachem root tabs
plants: amazon swords, wisteria, sagittaria (and I need some nice foregrounders I haven't decided yet)
fish: 4x yoyo loaches, 2 balloon molly, 3x sailfin molly
ferts: I've been using some of the AquaVitro line (mineralize, carbonize, envy) and floruish excel. I meant to pick up propel instead of envy to start so I will probably need some propel soon.
photoperiod: 12 hours

Question 1: How much light do I really have?
When I was setting up my tank I took my light hood into the LFS who told me that the Actinic bulb that was in my hood currently wasn't very good for live plants. They recommended I swap to the PowerChrome Aquaflora 39w. I _THOUGHT_ that I had 39x2 watts of light I assumed (39w x2 bulbs = 78 watts / 55 gallons = 1.42 watts/gallon) from my corallife t5 dual lamp fixture. I realize that isn't a lot of light but from my research it seemed adequate for a low tech newbie. However upon investigation into ferts and co2 which led me to believe I would need more light it looks like I have a Corallief T5 dual and not a corallife t5 dual HO (high output). In the manual it shows the 36" model is 42 watts (21 per bulb). So is the 39w bulb I put in the thing only getting 21 watts each leaving me a pitiful 21x2/55=0.76 watts/gallon?

Question 2: What are some options you see?
If I could go back, I probably would have used a better substrate - I feel like I've started off at a handicap here. I like the look of natural tanks with sand as a topper but I have to contend with my wife and daughter who like their castle and fake waterfall (I suspect once their interested in my newly revived hobby dies down i can replant things a tad heavier and possibly even replace my substrate).

And a picture, as I hate all discussions of tanks without a picture :)
Very lightly planted for now, I really wanted to start of small and learn to grow most of my own plants.
 
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#2 ·
Majorwoo, welcome to APC!

1. It is a surprisingly common mistake to put T5 HO tubes in a T5 NO fixture. Is your Coralife fixture the extremely thin one, 1" tall and 4" wide? If so, it is a T5 NO. I once got several such fixtures in a Craig's List swap--they all had HO tubes in them!

When you put an HO tube in a NO fixture, the tube may come on and glow. But very weakly, and it will actually put out less light than an NO tube in the same fixture.

So your first step is to get some NO tubes for your fixture. Frankly, I hate pretty much everything Coralife makes. So I went to the hardware store and bought the highest Kelvin T5 tubes I could find. Using a PAR meter, I found that the hardware store 5500K NO tubes put out more light than the Coralife NO tubes, and were 1/3 the cost!

With 2 T5 NO tubes over your 55 gallon, you will probably have medium light. This is plenty to grow many types of plants, and you don't need to get CO2 to do it.

2. I am a big fan of the Walstad method, which uses low to medium light and a soil substrate. You can read up on it in El Natural, and there are several great threads in the library on mineralized top soil as a substrate.

There are several ways you could add soil to your substrate without tearing down the tank. You could freeze small blocks of wet soil in an ice cube tray, then use forceps to push these under the gravel. Just do a few at a time.

You can also wrap a spoonfull of soil in some kind of thin paper and push that under the gravel. The paper will decompose over time. Pieces of coffee filter work well; that paper is tough but thin, and doesn't have anything in it that could harm plants or fish.

The other thing you can do is just be lazy and wait. Don't vacuum your gravel, and over time decomposed organic matter will build up. (You can remove unsightly debris from the surface of the gravel.) This will have many of the beneficial properties of soil.

Good luck!
 
#3 ·
Thanks for the welcome and the help!

Yes, I have the very slim looking coralife

I also have a single T8 hood in the garage somewhere, when I took them to the LFS they had me use the coralife (dual bulb, seemed like more light of course)
I have not done any PAR measurements (although I read enough to know that watts/gallon is a lousy way to measure light however PAR meters are expensive). I am really excited to hear that my hood which the manual says is 42 watts (again 21 per bulb) will get me into medium light land! I was really expecting to be stuck in low light land until I decided to upgrade lights, and CO2, etc. If I just pick up generic T5 high K bulbs do I need to look for a particular wattage? I was worried if the 39w bulbs in a hood built for 21 watts was going to overheat the unit or something else.

As for the substrate I was reading that gravel can get better over time - I was actually thinking about the very light gravel cleaning method and let it develop over time. I even thought about during larger water changes maybe removing some gravel and adding some sand along the way to get a sort of sandy gravel look and seeing how I liked that. I might do the coffee filter idea and bury some decent substrate material inside of the gravel to help speed up the development - that sounds pretty nifty.

I just swapped the powercrhome 39w t5 back to the actinic light that came with the hood and the color difference is noticeable - it's almost certainly much less light. I'm guessing this is more a less visible light/color spectrum thing to me as you said the non HO lights would be pretty dim in a non HO hood?
 
#4 ·
I also have a single T8 hood in the garage somewhere, when I took them to the LFS they had me use the coralife (dual bulb, seemed like more light of course)
Please forgive my cynicism, but the reason they told you to use the Coralife fixture is that Coralife tubes are much more expensive. That said, you do have more light with 2 T5 NO tubes than 1 T8. If you want, you could add the T8 fixture if all that will fit on the tank, and boost your light.

I have not done any PAR measurements (although I read enough to know that watts/gallon is a lousy way to measure light however PAR meters are expensive). I am really excited to hear that my hood which the manual says is 42 watts (again 21 per bulb) will get me into medium light land! I was really expecting to be stuck in low light land until I decided to upgrade lights, and CO2, etc.
My estimate that you have medium light is based on measurments with our club PAR meter.

If I just pick up generic T5 high K bulbs do I need to look for a particular wattage? I was worried if the 39w bulbs in a hood built for 21 watts was going to overheat the unit or something else.
The difference between 39w and 21 w IS the difference between HO and NO. I've never seen anything but T5 NO tubes at the big box stores, most places don't carry anything else.

As for the substrate I was reading that gravel can get better over time - I was actually thinking about the very light gravel cleaning method and let it develop over time. I even thought about during larger water changes maybe removing some gravel and adding some sand along the way to get a sort of sandy gravel look and seeing how I liked that. I might do the coffee filter idea and bury some decent substrate material inside of the gravel to help speed up the development - that sounds pretty nifty.
If you want to replace some of the gravel, there are better things to use than sand. Flourite, Ecocomplete, Turface, plain cat litter, and Safe-T-Sorb from Tractor Supply all have good cation exchange capacity (CEC). This is a measure of the substrate's ablity to absorb nutrients from the water (where algae can use them) and hold nutrients until plant roots can use them.

I just swapped the powercrhome 39w t5 back to the actinic light that came with the hood and the color difference is noticeable - it's almost certainly much less light. I'm guessing this is more a less visible light/color spectrum thing to me as you said the non HO lights would be pretty dim in a non HO hood?
Just to be clear, the HO tubes will be dim in an NO fixture. And the difference in the spectral output does make a differnce to how our eyes perceive the light. So you may have two issues going on here.
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#6 ·
Neither Lowes nor Home Depot carried anything in a T5 other then a 3500k bulb, so I ended up picking up a 21w 6700k Aqueon bulb from PetsMart. What is your opinion on the Coralife 10000k bulb as oppposed to a second 6700k?

Again, thanks for the help.
 
#7 ·
Ok, so it it looks like my corallife came with the reef setup of actinic and 10000k bulb. I've got (2) of the 6700k NO in my hood now.

Now I can go back to deciding how many ferts i want to use and if I'm going to build some co2 injectors and obsessing over other details that will eventually cause me to need more light if I'm not careful :)
 
#11 ·
Isn't that the truth! I have been finding the more I read the more I find people don't agree on the basics. 1-2 Low, 2-3 medium, 3+ high seems to be based on T12 standards, and not even necessarily with a correct spectrum bulb. It seems, that with my tank being 24" tall I'm running into more penetration issues - low lying plants may not get the light at the substrate level. (Of course, all based on internet research for however much that's worth)

I ended up swapping my substrate to 60lbs of Flourite black sand (Christmas present). I'm currently on the hunt for a foreground plant - I really like the dwarf hairgrass but I'm worried even with the aqua vitro line and flourish excel I just may not have the light for it. I'm think I'm going to throw my other single t8 hood up there and plant some - worst case it doesn't make it.

Thanks for your help. I hope I don't sound ungrateful - I'm just trying to learn and enjoy reading on something I'm interested in.
 
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