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Discussion Starter · #1 ·
How much lighting do I need for a 100g tank that is 22" deep from substrate to light? and for a 125g that is 21" deep from substrate to light?

Will fixtures of 260w PC work fine for this tank? I'm also planning on using compressed co2.

Thanks
 

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What kind of plants do you anticipate planting in the tank?

For plants that need low to moderate light 2 watts per gallon will be OK.

I have 2.7 watts over my 90 gallon tank (24" depth) and my hairgrass has hardly grown or multiplied in six months.

I plan on setting up a 125 gallon tank in the next few months and am planning on three banks of pc lights that will allow 1.5, 3.0 or 4.5 watts per gallon.

I plan on a a two or three hour noon burst of 4.5 watts and the rest of the day a lesser amount depending upon the needs of the tank. I think that amount of light is necessary for carpet plants and other light hungry stems.

Best regards,

PMD
 

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I've got 320 Watts, T5s running on my 110 Gallon and I'm growing Glosso on 10 hours a day lighting.

As PMD said though, depends on what you want to grow.
 

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It definitely depends on what you want to grow.

I have a 125 with 384 watts of PC lighting.
I use 1/2 for 9 hours a day, and put the other half on for a 2 hour midday burst.

For a while I was only using 2 bulbs, and my high light plants suffered, but I didn't have to trim 2 times a week. I think I've got a nice balance now.
 

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Discussion Starter · #6 ·
Thanks for your reply. I do want to grow hairgrass and carpet plants. Now I'm thinking in having a total of 356watts or 390watts. But with either one do I have to have all the lights on for 8-10 hours, or as many of you said just a midday burst for like 3 hours all the lights on?

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Lighting

Do as you please and see what works best. I leave mine on full for 10 hours a day. I've thought of rewiring and adding another 130 Watts (have the fixture) that comes on for only a couple of hours, but for now everything is growing fine. Many try to create the actual rising and setting of the sun, which is fine and gives you a different look at different times of the day. Does it make a big difference with plant growth? I couldn't really say, somebody else probably could. But for me, 10 hours full sun works fine.
 

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Wow, so much light! I have 1.6 wpg T5HO over a 100g (18" deep), and there's nothing I can't grow. From Tonina's to Erio's, if I can get it in my tank, I'll grow it. I use Blyxa japonica for a foreground, and growth is very tight, low, and it looks like I've got a yellow brick road in my tank. The lights on for 10 hours per day.

If I were you with a 22" deep tank, I would do 240w T5HO, or maybe up to 320w, but that sounds kind of high. Just my 2 cents.
 

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One problem I have is yeah do what you want or think but it costs you an arm and leg to put these systems on your tank. if its wrong then you need to buy new stuff.
 

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Tank Depth

I guess I should have mentioned my tank depth is 24", requiring higher light to penetrate the bottom, at least that's how I understand it and it seems to be working.
 

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SO what do you suggest?
If I'm understanding him correctly, I think he's suggesting that you'll hear differing opinions for lighting systems depending on who you ask. There are folks who will swear by MH, others who swear by T-5 HO, PC, T-12, etc. Some are more intense than others, but it also comes down to what you want based on expense, maintenance(higher, more intense light = more trimming and/or more, faster algae), etc.
Am I on track?
If that's what you meant, than I understand that if you buy an expensive PC setup (or whatever) and then find that it isn't intense enough or the plants don't do as well as you like, then you're pretty much out that $$, unless you can sell it, but either way you'll be out some $$. This hobby can be as expensive or cheap as you want.

I started in college with almost $0 budget. I bought a used 20H tank for $15 with some supplies and decor. I used DIY Co2 and used a 2x20w shop light from Home Depot. It worked ok. Not great though. Now my setup is a lot more intricate, but it gets better results and most importantly, I'm happy with it. That's the important thing.
 

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Thanks for all the comments. Avalon are you injecting co2?
Yep, only way to go.

There are certainly a lot of things to consider, especially when setting up a large tank, as the costs are generally higher. Lighting is one of the most misunderstood elements of planted tanks. Some may not agree with this, but let me explain:

We check out many others' tanks and the equipment they are using in order to gain a perspective of what will work, what won't, what cost is in our ballpark, and so on and so forth with the many variables--you know what they are, as I'm sure everyone has done it. The only problem is, do we know how well someone else's plants grow over the long term? We sometimes forget that a photo is only a snapshot in time. Are the plants still going to do well, 1 week, 1 month, or 1 year from now? What if you forget to dose? What if you have to go out of town on emergency and can't get something or someone to dose ferts for you? What happens then? I write this with highly lit tanks in mind.

But I encourage everyone to experiement. I encourage everyone to ask folks that are very experienced and have tried many different set-ups and various equipment. I've done high light & low light set-ups, and after many years, I finally figured out what I really want--something in the middle that can grow a wide range of plants. This meant for me that I didn't want anything really expensive like HQI, nor did I want to go too cheap, as I've learned to make an investment or it will cost you in the long run. I liked pre-made fixtures, but I couldn't find one to suit my needs, so I built my own (DIY in a canopy). Mine only cost $221 total doing the work myself, which was fun. It's "mid light," and I had my doubts, but I designed it to be expandable at minimal cost. I figured adding on would be easier than swallowing money unnecessarily spent. Turns out, it works far better than I thought it would! I had previously settled with the idea that I might not be able to grow certain plants, but I'm still amazed at what I can grow and how well they do. Uptake rates are moderate, so if I skip a day or three of dosing, there would be no huge algae invasion. Growth rates are moderate, so I don't have to prune every 3-4 days.

I guess my final advice would be to gather the pros & cons of different light systems. Consider what it is you want to achieve with your tank. Consider your experience level and if you're closer to beginner level, start slow and work your way up--we must crawl before we walk! And finally, enjoy and observe what you're doing, and find your own style. You can't simply put together a masterpiece the first time, but you can work on growing nice plants and discover what you like and don't like, all leading up to another 'scape, and another, and another, all while having a good time doing it, which is what this hobby should be about!
 

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Well said Avalon!
 
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