1) For the 40 or generally, what is a good GPH/LPH for that pump?
2) And, if I do want to try a drip wall on the 12x12 what would work? Thanks.
The first question
could get exceedingly complicated. It might have to, or it might not
have to. Answering a couple of questions yourself, might help begin to discriminate:
- what's your system water volume?
- are there any water quality objectives here, or do you merely seek moving water? filth is fine? or do you want sparkle?
I'm guessing filth would be bad, which suggests some need for filtration, which suggests some rules-of-thumb turnover rates. Pick a rate.
This rate, combined with system volume, and also head, will get you to pump size. That's how my mind works, anyway. It's not a beautiful mind. Ha ha ha. Surely others could shine more light on your issue.
Honestly though - I'm not gonna spend much more time on this, because I don't think this is what you ought to do yet
. Read on.
The second question
is much easier IMO. Any little piece of shit water-pusher will serve. Go cheap or go home. Ha ha. Now, this doesn't mean there's no details to work out, or choices to decide from. Some considerations:
- is the purpose of this drip wall simply to have some moving water to look at ("waterfall lite"), or is it more to water plants? put enough (duration, volume, flow rate etc) water on it, and you'll quickly
run out of plant options ("got algae?")
- where is your water reservoir going to be? are you just going to have the tiny little volume beneath the false bottom, or will you be draining into...something else? Somewhere else? How far under the tank?
My drip walls are about moss, mostly. My moss is growing mostly on cracked-cork mosaics - not on the cork, but atop the LFS stuffed between the cork pieces. Moss species that like it drier are free to try establishing on moister areas of the cork. The LFS is a great moisture buffer - as long as I briefly soak it every day, the moss kicks ass. Soak it, then let it dry quite a bit. Not
perpetually sopping wet! (Maybe I'm not running proper drip walls? Hmm. Ha ha ha. Moss walls then.)
So anyway - I run my little pumps 2x/day, just for 3-4 minutes apiece (using an off the shelf electronic timer).
- I use tiny little pumps.
- I use airline tubing for distribution lines, with holes melted with heated sewing needles spaced every cm or so along the stretches I want water coming out.pushing water through airline hose, emptying out of pinholes. Not spraying, just drip-drip-dripping.
- Consequently the through-put water volume is miniscule. I just drain into dump buckets, and suck out of a fresh reservoir. No filtration, no recirc.
- Honestly I'm probably applying a few ounces to the drip walls a day. The moss sponges up nearly all of it. I hardly ever have to dump my drain buckets. I top off my reservoirs on Saturdays. Usually I add maybe a pint to a quart - that's my consumptive use. Tiny. So sweet.
My advice is to make yourself a drip wall or five or ten BEFORE ever
trying a waterfall or stream. Many of the foundational principles apply to both situations. One route (drip wall) is cheap and totally inconsequential. The other (waterfall) costs more cash and hours, and Mother of God you can make a mess. A mess of a viv, a mess of a house or apartment. So start small, and learn from first-hand experience.
I (and others, I'm sure) don't expect to be done already with you here - if you have more questions just ask. But please also do your research, here and elsewhere.