How Much Light For 2 Gallons?

[TammyLiz]

I'm making a little custom light fixture for my 2 gallon nano. It'll be a bit above the surface since it will be mounted under a cabinet. I'm going to make a screw in fixture and I have a bulb here I am going to fit into it and I'm wondering if I made the right choice.

15 watt compact flourescent screw in bulb
800 lumens
6500K

They also had one that was 20 watts. I can't remember how many lumens but it was the same color temperature. I'm going to be using excel to try to keep the algae down. Which bulb should I use? I understand a smaller tank needs more watts per gallon, but how many?

 

[Dude]

I'm making a little custom light fixture for my 2 gallon nano. It'll be a bit above the surface since it will be mounted under a cabinet. I'm going to make a screw in fixture and I have a bulb here I am going to fit into it and I'm wondering if I made the right choice.

15 watt compact flourescent screw in bulb
800 lumens
6500K

They also had one that was 20 watts. I can't remember how many lumens but it was the same color temperature. I'm going to be using excel to try to keep the algae down. Which bulb should I use? I understand a smaller tank needs more watts per gallon, but how many?

isnt 15-20 watts too much for a 2 gallon ?

are you useing co2?

and what do you want to grow...?

 

[TammyLiz]

I have no idea how much light a 2 gallon would need! Thats why I'm asking. Hopefully there is someone who has done something similar and knows how much the WPG is skewed on such a little tank.

I won't have CO2 but I'll be using flourish excel.

I have another thread with pictures where I asked about lighting, but it is actually over four pages back by this point. I guess a topic name like "browning anubias leaves" doesn't do much to attract the lighting gurus. Here it is. http/www.fishforums.net/index.php?showtopic=142727

I guess I can go ahead an post the pic here, too.

In the back where you can see the hornwort and java fern sort of just floating there, I'm thinking I'd like to replace those with a stem plant of some sort. In the rear to the far left there is a crypt wendtii red that melted but I'm counting on it coming back. I'll add some dwarf hairgrass or some dwarf sag or anything else short that someone may suggest on the right in front of the wood. I wouldn't mind having carpeting over the rest of the substrate to the front right, but I am not sure how the lighting is going to work out with that. The anubias will hopefully be shaded by the stems growing up behind it.

This is the first scape I have seriously attempted, so I am completely open to warnings on any bad ideas I may be having. I've never used excel so I'm not sure how much that will affect growth and if it would be enough to have a carpet without serious algae problems.

I measured how far above the surface the light is going to be and its about 6 inches.

EDIT: BTW I think I figured out what was making the anubias leaves brown. I remembered that I used spring water in a 50% water change I did. The other day I did a water change on another tank and used the spring water and all the healthy hornwort completely defoliated and died. So don't use spring water. I'm probably the last one to figure that out.

 

[cheesemaker]

Your pico setup looks cool.
Is there a filter anywhere? It is almost like a biosphere.

Anyhow, not an expert on small tank setup but 15watts does sound alot for a 2G setup. However, because it is small and the surface area to volume ratio is much higher to conventional setup eg 40-60G, so... i guess light requirement would be less. That's my guess.

On the other hand if 15 watt works and no excess algae, it would be cool.

nice setup once again. Might try it myself some time.

 

[TammyLiz]

Thanks you! I am extremely flattered that you'd consider copying.

There is a filter, but not much of one. Its a diy sponge filter. It gets very dirty in a week between cleaning it out, and its a little hard to get to. We'll see if it actually pans out or not in the long run.

EDIT: You can actually see the uplift tube, a pvc pipe, in the back on the right, partially hidden by the driftwood. I can't decide if it is too noticable or not. I can't remove it for pics without ripping the filter apart.

 

[Themuleous]

I think you'd be ok with 15w, that'll give you 7WPG, Ive got around 8WPG over my nano (like in my sig) with no problems. However if you do add this light, you'll certainly need to add CO2 or you'll get the algae monester in a matter of seconds.

 

[TammyLiz]

Themuleous, I was just catching up on reading your journal. I remember seeing it before but hadn't read the whole thing. Its a little long.

I learned something new because I didn't know that algae was worse in a low current area. Is that because the CO2 doesn't reach there? I don't have much current in the tank. I was planning on using seachem's flourish excel without CO2. I'm wondering how much that helps with algae compared to CO2. I really don't know, and haven't found any definative examples to help me find the answer. It seems it would help a lot if it was really helping the stems out.

After looking at that I think I can safely say that 15 watts has got to be too much over mine. So I'm thinking about using a 10 watt bulb instead. Or use CO2, but I'd rather not for now since I have no supplies for that. I could do an experiment with the excel and the higher light but without some sort of encouragement from someone that it may work, I hesitate.

Someone let me know how much excel really helps.

EDIT: After some thought I should not go for high light, but medium will probably be OK? I wonder, does anyone know how many watts would be medium light over this tank? Err, well, not tank, but you know.

 

[Themuleous]

Haha I like to keep it updated!

I wouldnt necessarly say low water flow = algae but in my experience certaily the BGA seems to be worse in areas that have less flow.

As to the excel, I know that if you dose as 2 or 3 times the recommended amount it will kill BBA but I dont know of anyone who's tried that long term and/or its effect against algae at normal rates. Its supposed to be quite a good product and it my help in keeping your plants in good heath which in turn will help fight the aglae. However, its very expensive and for around 20quid (about the same as two bottles of excell) you can get a yeast type CO2 kit that'll work better and save you a fortune in the long run and the excel needs doseing daily whereas a CO2 kit will last betwenn 7 to 10 days. That said if you want to try excel, considered this the 'encouragement' you wanted, go on give it a go, with a betta in the tank its not like you'll have to worry about it not getting enough oxygen. Then you can report back with your findings

As to the lighting thats a tricky one, the whole WPG rule doesnt work in the same way for smaller tanks and yours is certainly small! but I would think the something in the region of 2-4WPG (i.e a 4 or 8w light fitting) would probably be mid-range but I cant promise anything on that. And you may find it hard getting plant light bubls that are that small the smallest arcadia tube Ive seen is 6w i think.

HTH

Sam

 

[TammyLiz]

I also have a 10W 6700K bulb I could use. But if I make this type of fixture (screw-in), I wouldn't be able to go any lower on wattage without lowering the color temperature as well, based on what I have seen available. So I will go with that one and see what I can do with the excel. I already have a bottle of it so I might as well try it.

 

[Themuleous]

Worth a try let us know how you get on

 

[Graeme Edwards]

I have a 2 gallon 8 ltr cube and i have a 20W halogen spot lamp on mine which gives me 9WPG thats US gallons with Co2 added.

http/www.fishforums.net/index.php?showtopic=137624