lighting a 20 gallon long

[luxum]

I've been considering retrofitting my hood with PCs from AH supply, but i need to know how much more light a PC throws versus normal fluorescents.

Here's the situation. I have a 20 gallon long (30"x12"x12") with an Eclipse3 hood with the filtration disabled in favor of my canister. It has a dual T8 lightstrip (2) @ 17W, 24" placed front and center. This leaves the sides and back of the tank darker. That is not really a problem, i have lots of low light plants that are growing pretty well in the shadowy corners. I would like to get a bit more light into the front center of the tank, enough to grow one of the less demanding carpet plants. My options are, get the 2 13W PCs, or a single 36W. I know that a PC of any given wattage is brighter than the equivalent wattage fluorescent, but i don't know how much. Would either of those options get me a bit more light in the target area without making it too bright for my lowlights?

I'm also considering rigging a moonlight system in the space currently occupied by the old filter space, i can cut that part off with a dremel as needed... any ideas?

Edit: thanks for moving this to the appropriate forum!

 

[Colin_BC]

Is a PC a power compact fluoro? I know 13W is the most common size for a compact fluorescent lightbulb. I know them as CPF's, if this is what your referring to. If not, what is a PC? I'm having a tough time keeping up with all the acronyms you see everywhere on the net

Colin

 

[luxum]

Oh, i'm sorry! Yes, i'm referring to what AH Supply calls power compact fluorescent. The 13W or 36W size will fit my hood.

 

[Lateral Line]

>>> oops i meant this to be in DIY, sorry.

"Alacazam!!!"

There, now it is!

Watch the spectrum of those lamps, a lot of them have a very low value, 2700K or similar. You want 5500K - 6500K lamps for plants.

 

[luxum]

Perhaps i should re-phrase my question!

What wattage of power compact fluorescent (like they sell at AH supply) is the equivalent in brightness to 50W of NO fluorescent? I can't seem to find a conversion factor...

 

[Colin_BC]

Could you post a link to some at AH? I'm guessing that these are going to be different than what I mention below, but it may help you or someone else.

The "equivalant brightness" your looking for could be measured in a Lumens comparison. Lumens are not the only factor (eg. spectrum), but they're more readily available to compare and give you a good idea if your looking at non-LFS places.

Try this to give you an idea. I gathered all this when trying to determine what lights to use on my hood. I went with the 23W which are about the same as the 25W, but easier to find. 42W CPF is 3x that of the 23W in cost. 50W Incandescent bulbs aren't mentioned, unfortunately. This is all taken from labels and packages. The lumen output may vary with some bulbs, but only slightly. Most aquarium-intended packaged bulbs don't list lumens that I've seen, but if you're doing anything DIY-wise or improvising, most other bulbs you'll find do list lumens.

WATTS----------LUMENS
40W-Icdst--------- 300
60W-Icdst----------565
100W-Icdst--------1750
4’-Fluoro-40W-----2960
CPF-9W-------------540
CPF-14W------------900
CPF-19W-----------1100
CPF-20W-----------1200
CPF-25W-----------1500
CPF-27W-----------1750
CPF-42W-----------2600


Colin

 

[luxum]

Could you post a link to some at AH?

The kits i'm looking at are at www.ahsupply.com, the different sizes are linked on the left.

 

[Colin_BC]

I see.... As you can see in the kits they sell, the ballast located seperately from the bulbs to help with heat. The ballast is what get warm on any fluoro's. Looking at what they have, push come to shove I would go for the 36W, but I personally prefer min 2-3 watts per gallon. The 36W should do for low light plants, but I don't know if carpeting plants will do to well.

Colin

 

[luxum]

Thanks for your responses. Maybe i should consider the single 55W, that'd be 2.75 WPG... i'm just worried i'll end up with too much light and have to mess with keeping the parameters in balance, i don't want to have to deal with CO2 in particular.

 

[Colin_BC]

If it comes to it, don't be intimidated by CO2. Once I hit 2 WPG, my LFS owner suggested a good substrate like fluorite and CO2 before spending money on any more or better lights. I bought both. You can make your own CO2 unit, but the bubble diffuser can be hit and miss. You can buy the diffuser panel seperate for $25 (CAD), but you still have to mix and measure the yeast and sugar and keep a steady temperature and all that crap. I had no problem building my own canopy in the end, but I'm still glad I spent the $40 on the whole CO2 store bought (yeast) model. It has a thermal cannister, bubble diffuser and came with 3 packs each of the yeast and stabilizer. I filled sugar to the first line in the cannister. I added water to the second line. I dump in a pack of yeast and stabilizer, seal it up and hook the airtube from the diffuser (included) to the lid of the cannister and forget about it until the bubble production slows too much (1st pack lasted me 6 weeks, was still going but I changed it out of boredom).

Just keep this in mind for if (and when, trust me ) you decide or your plants decide that it is needed.

Colin

 

[luxum]

Hehe. Well, i changed out the substrate for pure flourite a while back, recently topped that with some black sand to fill in some depressions, amazing root growth... i wouldn't mind a higher light tank if my low light plants wouldn't get fried. I have a small fortune (to me anyway) in anubias and crypts, wouldn't algae outcompete them in a high light tank?

How do you deal with the Ph swings at night? Is your CO2 diffuser on a timer or something? It just seems so fussy and delicate, i'm afraid that one mistake and i'd wipe out the fish, i've read so many horror stories.

 

[Lateral Line]

Higher plants are more efficient users of nutrient then algaes. A well balanced planted tank rarely has algal problems as nutrients are the limiting factor.

 

[luxum]

I understand that, but aren't "well balanced" planted tanks generally full of fast growing, high light stem plants? I keep reading that i can't put low light plants like my anubias species in high light or they'll end up covered in algae. Is this a misconception?

 

[Colin_BC]

Is your CO2 diffuser on a timer or something? It just seems so fussy and delicate, i'm afraid that one mistake and i'd wipe out the fish, i've read so many horror stories.

Have a look at this. The cannister is the round black thing on the back of the aquarium. The bubble diffuser is the plastic thing hanging on the inside of the aquarium. No control valaves or regulators. This is meant for smaller aquariums, under 50 gallons. You mix the crap in the cannister, hang it and plug it in and watch the plants grow. It bubbles at a rate of 1 bubble every 5 seconds or so once it's established after a couple days. Here's a link to the one I bought so you can have a better look: CO2 Natural System. If you're in the states, change the ".ca" to ".com" and it will give you the US price.

As for the pH swings at night, never noticed. My pH is pretty stable fortunately.

Colin