Backyard Aquaponics
A place to discuss aquaponics

WOW are they 1m length or something. thats really cheap.

Nope 6 metres. PM me if you want the details.

Did another test with the pump going straight into 1 1/2 inch poly pipe (40mmID approx)
66 litres/min or 3960 litres/hour
71 watts/hour

Outbackozzie you were pretty right with your prediction. I expected a gain but not that much. When you look at 32% more water for 7.5% more electricity really shows the importance of matching pipe size to the pump.

Jet
Are low pressure, high volume pumps affected more by pipe friction than high pressure pumps?

regards
bj4408

The lower the pressure the pump, the more a restriction will affect flow.

Theres a fair bit to it but the more highly efficient a pump is the more sensitive it is to changes in discharge/suction.
We tend to notice head loss on a low head pump because there isnt as much to start with. Often low head pumps arent that efficient either, usually cheap makes too. These pond pumps are unusual in this sense, low power use AND fairly high flows

Just some sample numbers on pipe headloss
10m of each size PN6 PVC flowing 6000lph
50mm = 11cm headloss
40mm = 23cm headloss
25mm = 177cm headloss
25mm LD Poly = 187cm headloss and velocity is regarded as possibly damaging to pipe (wont happen but its over 3m/s)

Or less than 1m of 25mm PVC has same headloss as 10m of 50mm PVC

Good reasons to use as big a pipe as you can

Nice post Jet

Thanks
Forgot to metion fittings - elbows, tees, joiners and valves also contribute heaps to headloss too

Ordered one of the 16000lph lagunas today for the school FT from a different Australian online supplier to that linked by OBO that had a lower price. Link below.

http://www.thereefshop.com.au/index.php?main_page=product_info&cPath=14&products_id=1235

I think they worked out more expensive with postage than the other shop.....or maybe they were out of stock.

Special price at the other shop has finished so it ened up cheaper, postage was $31.

But I think Age of Aquariums do price match and I think by 10% as well.

and only 7.50 postage too

so excuse my n00biness guys, is it better to go the bigger pipe diameter - biggest you can? Are you not restricted by the size of the outlet

I have 19mm HP poly pipe connected to my 5000 ltr per hr pump, should I look at 25? Worth doing at test at 1 meter with both then?

Go the biggest size of the pump outlet...

Do your test with 19mm and 25mm.... you will be surprised as to the difference in flow....

cheers - pretty sure it took 25 as well - will test tomorrow