Wpg. Is That Imp Gallons Or Us Gallons?

[markandhisfish]

when working out the wpg which gallons are used? is it imperial (uk) gallons or us gallons?

 

[Verminator89]

US Gallons usually for the WPG rule matey. Thats what Tom Barr and George Farmer reiterated to me when i started on the planted side.

 

[markandhisfish]

in a 30usg ( when empty) do you agree that it would be fair to say that once you figure in substrate internal filter etc , that i could class that as more like 25 usg?

i rekon most im going to be able to get in there is 3x18w 24" tubes giving 54w do you rekon that by the time substrate etc is taken into account i could get away with classing that as 2wpg?

 

[SuperColey1]

Stop chasing light numbers. Its a mathematical very rough estimate of what you have and 2WPG is more then enough for any plant. 1WPG with pressurised is fine for all IME.

2 x T8s that are the full length of the tank is enough for all plants. (Preferably on an electronic ballast so the tubes are good for 2-3 years)

I've seen quite a number of posts from various people talking about water displacements etc.

Always when using guides take the tank volume and not water volume. It is impossible for you to work out how much water is contained in the substrate, in the plants, in the wood etc. Then you would be adding back the water in the filter etc.

Just go by what the volume of the tank is in US gallons.

AC

 

[markandhisfish]

basicly the tank i just bought has a built in light unit it the hood which holds 2 24" t8 tubes which are 20w but are old and knackered . im going to replace them. looking on lampspecs ive found 24" 18w daylight tubes . i was going to modify the hood to accomodate a 3rd tube to try and get 2wpg as reccomended here for high tech tanks

http/www.fishforums.net/index.php?/topic/298133-back-to-basics/

 

[SuperColey1]

basicly the tank i just bought has a built in light unit it the hood which holds 2 24" t8 tubes which are 20w but are old and knackered . im going to replace them. looking on lampspecs ive found 24" 18w daylight tubes . i was going to modify the hood to accomodate a 3rd tube to try and get 2wpg as reccomended here for high tech tanks

http/www.fishforums.net/index.php?/topic/298133-back-to-basics/

Have you bought a Fluval 125? Those tubes may say 20W but they are running on an 18W ballast. If it is the Fluval 125 then they are probably running on 15W ballasts. The ballast dictates the light you get.

so you'll never get 20W no matter what the manufacturer states and it is hard to find any 20W ballasts.

More than likely they are also using magnetic ballasts. This is fine but means they flicker start the tubes and they degrade quicker (1 year replacement)

If they were using up to date electronic ballasts then the tubes would last 2 to 3 years.

On the article.

No offence to Aaron but I think he updated an old article that we had on here which even now after such a short time could do with a re update. This hobby has advanced very quickly over the past year or 2.

When we write articles we do have to sometimes write bearing in mind that there are many that refuse to believe things. The EI 'reset' is not much to do with removing build up of nutrients but we can phrase things that reassure those who want to convince themselve's of this.

With light if we said you only need 1WPG for any plant then we would have thousands of the high light obsessed refusing to accept things so there is a compromise. Where they say you HAVE to have at least 3WPG for certain plants I would suggest. Nope up the CO2 and stay at 1WPG

Its playing safe really. The articles has to be factual but also remain credible and to remain credible it can't be ultra revolutionary or be a zillion miles away from what all the experienced scapers will say.

0.9WPG will grow the 'highlight' plants IME require very good CO2 though.

So a little clarifier. Can you scape with your setup? Yes I have done so and so has this guy (George Farmer)and this is with magnetic ballasts. Most likely the same setup as you are looking at regarding tank and lights. Key thing is very good CO2.
http/www.fishforums.net/index.php?/topic/208540-125-l-33-gal-low-light-low-maintenance/page__p__1728097__fromsearch__1&#entry1728097

Now the Americans (with the exception of Llj) will jump straight on me here and say 'They are all low light plants'.

When the journal above was written that was the mainstream view. Lowlight this and lowlight that.

Only 3.5 years ago but the mainstream view was that highlight plants needed 3-4WPG. I would like to think we have moved on from there though and have a little more understanding however there are still many (possibly the majority) that still believe this and whack loads of light above the tank.

So while someone would suggest that the success in that tank is because they are low light plants. I would say that a full stem aquascape can also be succesful in the same conditions. Good CO2 needed. The reason that the tank above is low maintenance is the choice of plants rather than the light itself. They are slow growing plants. Even under highlight they are still relatively slow.

So 2 x 20W (be it 18W or 15W actual) is the same as the scape above.


AC

 

[markandhisfish]

hmmm . very interesting. i think the tank is an old fluval . the only "branding" on it is "light glo" 80x35. punch this into google and most of the results are german , but all bear the word hagen which if im not mistaken is fluval. each tube has a basic reflector , simply a curved piece of white plastic above the tube.

the tubes im probably going to get are philips 24" 18w t8 daylight tubes. so lets say for arguements sake the balast actually gives 18w from each tube , then that gives 1.2wpg
how much difference these reflectors make i guess is debatable.

do you think its worth me bothering with the extra tube or not?

after reading your reply im not so sure tbh

also not sure if this is important or not ( depends where you read) but they are 1300 lumens and 6500 kelvin

 

[SuperColey1]

. the only "branding" on it is "light glo" 80x35. punch this into google and most of the results are german , but all bear the word hagen which if im not mistaken is fluval. each tube has a basic reflector , simply a curved piece of white plastic above the tube.

Its a Fluval Duo Deep 800. Same tank as I still have (and bought second hand in 2006.) The ballast is a 2 x 15W. Call the volume 33USG

Same tank I 'upgraded' the lighting in 2007 to............2.5WPG doing just what you are thinking of now Like I say we've moved on a bit now. I 'downgraded' to 0.9WPG of T5 just a few months later. Still got very good growth due to good pressurised CO2.

You need to buy some reflectors to replace the white plastic cent pieces. Cheap £5 ones from P@H will suffice. They just clip onto the lights.

With the Philips you will be fine. Forget the Lumens. that just means it looks bright doesn't tell you how much light is being put out. 6500K is the colour-daylight. It will veer toward green but not too much. Use one with a lamp in the 4500K area (slightly pink) will give a more natural colouration.

So no need for 'arguments sake' You will have 30W over 33USG May be worth finding a 2x18W or 2 1x18W electronic ballast on ebay and wiring it in yourself. the ballast is hidden within the hood. The access panel is on the top.

I wouldn't other with another tube. Not much room in those hoods but the tubes are quite well spaced.

Have a play with a screwdriver prising the access panel open and take a look inside It will be hard to remove. It is glued as well as clipped.

Tankside:

Outer with access panel removed:

AC

 

[markandhisfish]

yep thats the same hood reflectors it is then no point wasting money on things that arent needed