how long can airtubing be before it degrades a pump power?

I want to upgrade to a commercial pump but i want to put it in my attic to muffle the sound. The one im currently looking at is a 35 watt one and im thinking of running 4-8 lines from the attic to the buckets (8 feet below the pump).

8 ft runs should be no problem at all. Just make sure you get a good manifold though.

Cool, any 40-60 dollar pump you'd recomend for 4 buckets (1 extra bucket for the tea used sparringly)? I have 2 twenty gallon ones doing all the work right now :-/

Just looked all over my pump for brand, couldn't find name anywhere. lol
But its a 35w and i use a manifold with 6 lines run anywhere from 2 to 12 ft wth no problems at all.

The pressure drop in compressed air lines can be calculated by using the formula

• 1 kg/cm[SUP]2[/SUP] = 98068 Pa = 0.98 bar = 0.97 atmosphere = 736 mm Hg = 10000 mm H[SUB]2[/SUB]O = 10 m H[SUB]2[/SUB]O = 2050 psf = 14.2 psi = 29 in Hg = 394 in H[SUB]2[/SUB]O = 32.8 ft H[SUB]2[/SUB]O

Or, just buy the biggest damned pump you can afford.

Seriously - the pressure in a line drops quickly once leaving its compression source. This is the reason for turbine booster stations along pipelines. 8' lines are ridiculous if running multiples. Promise you the weak air flow once all are connected will be disappointing. Add the stupid airstones everybody believes in and you have a bigger drop in the amount of air actually supplied to the solution/res.

hotrodharley said:

Seriously - the pressure in a line drops quickly once leaving its compression source. This is the reason for turbine booster stations along pipelines. 8' lines are ridiculous if running multiples. Promise you the weak air flow once all are connected will be disappointing. Add the stupid airstones everybody believes in and you have a bigger drop in the amount of air actually supplied to the solution/res.

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Thanks, this was helpful. I'm a noob and didn't realize this. Running a commercial air pump (ActiveAqua 60W 70L/min) and I didn't ever think that it might not be enough for 8 lines at 10-12 feet each. Going to shorten these as much as possible soon.

What do you recommend instead of the airstones? The diffusers that make smaller bubbles?

Run 1 main line down to your room then place a manifold close to your buckets. Your not inflating anything just pumping air.

True. He just wants/needs to pump all the air he can and all the air he paid for with the pump.

BTW - topfuel suggests using stainless steel screws in the ends of your air lines. Screw them in and adjust the air flow by screwing them in or backing them out. Better to regulate the flow/pressure right at the dispensing end - in your res. I was using just plain air tubes weighted and dropped in and I get heavy yields and healthy roots. But the last 2 setups I have tried topfuel's screw trick. You can hear each pot now with different flows as needed.

ATTENTION: STAINLESS STEEL.

hotrodharley said:

True. He just wants/needs to pump all the air he can and all the air he paid for with the pump.

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Good point.

nick88 said:

Run 1 main line down to your room then place a manifold close to your buckets. Your not inflating anything just pumping air.

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Thanks. More noob questions:

If the pump itself is several feet higher than the manifold, is there any need for a check valve to prevent any backflow in case something goes wrong?

I was going to set it up like this: airpump would be hanging from a bungee cord about 5 feet up and then run down through tubing (3/8" I think?) for 6 feet to the 8 port manifold that sits on the cold concrete floor. Then the 1/4" tubing would be going up about 12" to the hole at the top of each bucket. Any risk of getting some sort of back flow this way? Should the 8 port manifold be higher than the buckets as well? Not using any check valves.

I second that question and i lucked out on fining some screws for now. I bought a tetra 100 gallon pump to go with the 2 20 gallon ones i already had. Hope its enough for the four buckets :-/