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Old 31-03-2004, 03:01 AM
Macbrush
 
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Default Need advice on a 200 gal tank

Thanks for the reply. 25 bags of Flourite sounds much more reasonable, I
didn't quite get what Seachem's instruction means, and wrongly guessed it at
40+ bags, now there is some money to spare for the heat cable. :-)

I still haven't decided on the lighting side, since my current 35gal is on
very bright side, 8+W per gal, I just don't feel very confortable with such
dramatic drop. Now I might just go for 3 X 250W HQIs. But then I still have
3 weeks before the new tank is in place, I still have time to think it over
again.

And the good news is that a guy in my local message forum is selling a 1/2
hp chiller very cheap, so I guess I have one problem solved.

Thanks
Kenneth

"Michi Henning" ???
???...
"Kenneth Ho" wrote in message
om...
As I mentioned in another post, I am preparing to replace my 35 gal
tank by a 200 gal monster.

[...] (the tank is 72" X 24", and I want 5" front and 8" back)


Hmmm... You don't give the third dimension of the tank. Is it 24"
deep or 24" tall?

If the tank is 27" x 24" x 24" (which is a common size), that's
150gal, not 200gal.

To get 200gal at 72" long, the tank would have to be 24" deep and
32" tall, or 32" deep and 24" tall. Either way, consider the maintenance
issue: with anything over about 24" deep and 24" tall, it is no longer
possible to reach the bottom rear areas because you run out of arm :-)
Makes it very difficult to do anything like replanting. Just a thought...

How much light would you guys recommend me to have? I am thinking 4 X
150W HQI.


Assuming 72" x 24" x 24", I wouldn't go above 3 x 150W HQI. (I have a tank
that size, and I'm running 2 x 150W HQI plus 2 x 38W T8 tubes. For my

taste,
that's just about right, or a little on the bright side. I guess I could

use 3
x HQI
instead, but it would become harder to keep the tank in balance. I

definitely
wouldn't use 4 x 150W for a tank that size.

Even if the tank is 32" tall or deep, I'd probably still not use 4 x 150W,
which would be 3W per gallon. Doable, but maintenance-intensive and very
bright.
At that light level, you need high levels of nutrients and CO2. In turn,

that
means endless pruning, which can be a lot work. Or you can let nutrient

and
CO2 levels drop, but then, at that light level, algae are likely to
get the upper hand. 3 x 150W would still give you ample light, reduce the
amount of maintenance, and allow you to grow even light-hungry plants.

How many bags of flourite should I expect, roughly? (the tank is 72" X
24", and I want 5" front and 8" back)


Seachem recommend 1kg of Fluorite per 200 cm^2 to a depth of 5cm, which
is a complicated way of saying "1kg per liter of substrate." If you want

to
cover
a 72" x 24" area to 5" at the front and 8" at the back, that's 72" x 24" x
6.5".
Allowing for 1/4" glass thickness, that gives you a net volume of 174

liters.
Fluorite is shipped in 7kg bags, so that would be just under 25 bags.

Not cheap. I suspect that you would get equally good results by using,

say,
eight bags of fluorite and top up the remainder with gravel. That's pretty

much
what I did with my tank -- about 30% fluorite, 70% gravel. Plants grow
better than I would like them to :-)

Is there any CO2 reactor available for this size, or I would have to
go for 2 - 3 reactors?


No, a single reactor will do fine. Check out the Aqua Medic Reactor 1000.
You can find it at www.aqua-medic.de. That one is good for up to 500gal
and fits outside the tank, so there is less clutter inside. I'm using that

one
myself and I'm very happy with it. It achieves 100% CO2 solution and
easily plumbs into the output path of a canister filter. You can find

similar
reactor designs from other manufacturers.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com