Watts Per Gallon

[JustKia]

I'm a little confused - nothing new there then...

When working out the WPG for your tank does a 24" T8 36W tube really count for the same amount of light as a 36" T8 36W tube?
How so?
I get that it's still 36W but surely you're getting more light from a 36" tube than from a 24" tube?

I'm trying to work out what I've really got (theoretically).
My tank is 72Gal but is a delta, not rectangular.
2x 24" T8 Arcadia Freshwater 18W tubes
2x 36" T8 Juwel Daylight 36W tubes

I seem to get a much nicer colour (although what the plants think I have no idea) from the Arcadia ones.
Should I stick with the tubes I've got or look at swtiching some/all of them out?

Right now I've not got any CO2 running. I looked at the DIY CO2 but seems they're only good for smaller tanks and I'm not sure I want to get into the whole fire extinguisher thing atm.
I've just ordered a drop checker so I'll pop that in when it arrives and see where my natural CO2 is at then come back for more advice on that.

So, first things first is to work on the lighting - if my calcs are right I've got 108W per 72Gal = 1.5WPG?

 

[Jallen]

When working out the WPG for your tank does a 24" T8 36W tube really count for the same amount of light as a 36" T8 36W tube?
How so?

Impossible. All tubes are standard wattage given their length and diameter. T8 tubes are 8/8ths of an inch in diameter and each length of a T8 tube corresponds to a wattage. You cannot have 2 T8 tubes of the same length with different wattages.

 

[JustKia]

T8 tubes are 8/8ths of an inch in diameter and each length of a T8 tube corresponds to a wattage. You cannot have 2 T8 tubes of the same length with different wattages.

Ah, gotcha thank you, that then makes perfect sense.
I confess I did not know that length corresponded to wattage and hence my confusion

 

[baron von bubba]

I'm a little confused - nothing new there then...

I'm trying to work out what I've really got (theoretically).
My tank is 72Gal but is a delta, not rectangular.
2x 24" T8 Arcadia Freshwater 18W tubes
2x 36" T8 Juwel Daylight 36W tubes

I seem to get a much nicer colour (although what the plants think I have no idea) from the Arcadia ones.
Should I stick with the tubes I've got or look at swtiching some/all of them out?

I've just ordered a drop checker so I'll pop that in when it arrives and see where my natural CO2 is at then come back for more advice on that.

So, first things first is to work on the lighting - if my calcs are right I've got 108W per 72Gal = 1.5WPG?

lighting should be fine. tube colours are pretty much for your benefit, don't get wrapped up thinking you need "special" plant grow tubes, its mostly marketing hype and the only difference is paying 3 times the price.

drop checker will be pointless, it will stay blue. i believe CO2 in a low tech will be constantly around 6-8ppm.

 

[JustKia]

OK, so if a drop checker isn't going to be much use (yet) how is the best way to see if I have stable CO2 and how will I know if I have enough CO2 for my lighting levels (or vice versa)?
Sorry, for all the questions - I'll get there one day I promise.

 

[baron von bubba]

OK, so if a drop checker isn't going to be much use (yet) how is the best way to see if I have stable CO2 and how will I know if I have enough CO2 for my lighting levels (or vice versa)?
Sorry, for all the questions - I'll get there one day I promise.

in a non CO2 supplemented tank the CO2 levels will be pretty constant, the plants will not use as much as the tank takes in thro the surface so it shouldnt vary much at all.

as for knowing if its enough for your lighting levels, well thats the hard bit! :0)
1.5ish wpg should be fine tho.

this could always be an option for you should you not want to go pressurized
http/www.aquaessentials.co.uk/index.php?...roducts_id=2988

 

[JustKia]

Thanks, will take a look