# Lighting requirements?



## Grebby (Dec 13, 2004)

Hi,

I have a 6'*18"*2' tank (2'tall), I know that I should be aiming for 1.5 W/Gal or more but does that account for reflectors etc? is this in US or Imperial Gallons?

I'm currently building the hood etc and would like to have some opinions.

I'm planning on having 10 ish Bed Bellys(eventually) in there and I know that Ps like low light but have also been told that they would get used to a high enough level of light to get good plant growth. What sort of lighting should I be looking at?

Thanks

Ian


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## sasquach (Dec 6, 2004)

when i askd that i got told that if the lighing is nice and bright helping the plants its ok because the piranhas get used to the light.


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## phreakah (Sep 20, 2004)

i have 110 watts of light on a compact flour. system on a 125gallon... with 7 caribe. the tank's pretty bright, and the fish seem to really like it. i dont even have plants, just a piece of driftwood. they are really active and have nice color.


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## Gumby (Aug 13, 2004)

One thing to keep in mind if you decide to go with powercompact bulbs is that the watt per gallon rule is not the same because the lumen output on PCs is much higher than that of regular flourscents.

On my 125(same size as your tank) I have the following:

One end(most of the plants):
1 36 inch Jebo Power Compact fixture with 2x 55watt 6700K bulbs
1 30 inch All Glass Power Compact fixture with 1x55watt 5700K bulb

On the other end: 
1 36 inch Jebo Power Compact fixture with 2x 55watt 6700K bulbs

All fixtures have built in reflectors. This seems to be plenty of light for all plants. I have 5 RBP and 4 Caribe in the tank. They're doing just fine and don't mind the bright lights at all.

If you go the PC route, be sure to get the 6700K bulbs, they seem to grow less alage than the 5700K bulb does. The alage that likes the 5700K spectrum is that tough green spot diatom(I believe) alage and it's a bitch to get off. Only way I can get it off the glass is with a razor.


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## phreakah (Sep 20, 2004)

i have the 48" jebo w/ the 2x55 watt 10,000k bulbs(it can hold 2 more but i dont have em in there).... im starting to get brown algae







im just gonna cut the lighting back an hour per day to see if it helps...

also, what do you mean by the wattage on PC is not the same? can i grow more or less high maint. plants with PC wattage as compared to standard flour? ie will my 110 watts PC be able to support higher demanding plants than 110watts of standard flourescent?


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## Gumby (Aug 13, 2004)

The lumen output(lumen is a measure of brightness) is much higher as far as the ratio of watts:lumen goes with PC. 
In short, yes, you can grow plants with higher lighting requirements under PCs.

As far as the alage goes, part of it could be the fact that you have 10,000k bulbs(better spectrum for SW tanks), but in all reality... high light= high amounts of alage growt and plant growth.

Time to invest in some alage eaters. In my 125 I have 4 or 5(not really sure how many are alive) Albinus plecos and 2 common plecos. I'm about to yank the common plecos out though, fookers are starting to nibble on my plants and I won't have that.


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## phreakah (Sep 20, 2004)

cool, thanks for the info.

Yeah, I have a pleco, but it seems like he only eats leftover pieces of fish rather than the algae on the tank hehe


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## Grebby (Dec 13, 2004)

Gumby said:


> One thing to keep in mind if you decide to go with powercompact bulbs is that the watt per gallon rule is not the same because the lumen output on PCs is much higher than that of regular flourscents.
> 
> On my 125(same size as your tank) I have the following:
> 
> ...


I was thinking of getting 4 30" Aqua-Glo Fluor T8 Fluorescents with reflectors at 25W a piece. Will that be enough?

There is a 180 liter sump under the main tank which is 510 liters. Will this be big enough for 10ish RBPs when fully grown?

Also how many should I get to make sure I have 10 when fully grown?

Sorry for all the questons but there seem to be an entirely different set of guidelines for piranha as oppossed to other fish.

Thanks

Ian


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## Gumby (Aug 13, 2004)

Technically you need at least 20 gallons for each full grown Pygo, so you'd really a need a 760 litre(200 gallon) tank for 10 full grown RBP.


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## o snap its eric (Feb 19, 2003)

lighting wattage depends on what kinda plants you have. Some plants can do from 1watt/gallon all the way up to 4-5watt/gallon.


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## Grebby (Dec 13, 2004)

o snap its eric said:


> lighting wattage depends on what kinda plants you have. Some plants can do from 1watt/gallon all the way up to 4-5watt/gallon.
> [snapback]800016[/snapback]​


UK or US Gallons?

Does that mean lights without reflectors or with?

Thanks

Ian


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## Seifer (Apr 10, 2003)

Grebby said:


> UK or US Gallons?
> 
> Does that mean lights without reflectors or with?
> 
> ...


with a tank that size you are not going to want to mess with normal flourescent lighting, you NEED compact lighting.


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