1 return pump to rule them all or 2, 1 for each tank?

[henward]

System

1x 600 litres (2 outlets) - 3k - 3.5k lph turnover

1x 1200 Litres (3 outlets) - 5k - 5.5k lph turnover

TOTAL TURNOVER: 8k to 9k lph turnover

compensating for age of pumps - 6500 to 7000 lph turnover of system

Sump: 200 litres

total wattage for pumps is approx 200w to 220w

currently i have 4x return pumps,

2x 3600lph pump (2000lph approx at 2 metres. 2500 lph 1.5m)

1x 1500lph pump (1k lph approx at 1.5 metres)

1x 6000 lph pump (3600lph approx at 2metres) - warrens old pump, confirming output with him, but if i recall this is right.

i have recently fixed my sump capacity issues, i can now pump through the flow at will.

i am thinking

1) consolidate, 1 massive pump

http://www.trademe.co.nz/a.aspx?id=458640179

165w total, would save me money in the long run - increase flow all around as well whcih is what i want, more flow!

By doing this i would construct a type of 'switch board'. a basic system that distributes water to the 5 hoses i have going into my 2 tanks. each outlet has a tap that would regulat the flow, i am more concerned about the flow to the 600 litre, overflow surface is smaller so wont handle as much flow, the 1200litre can handle much more.

(NOTE: most pumps come with a bypass valve to ultimately reduce flow if its too great.)

OR

2) 2 pumps, one for each tank.

getting rid of 3 return pumps, use my big one currently for the 600 litre

and get a biggish one, not a monster for m y 1200litre.

If i could have all feedback with pros and cons of both set ups. would be awesome, im torn, i mean i can make it work with both.

ultimately, fiscally speaking the 1 pump makes sense, am i missing something?

[henward]

http://www.hailea.com/e-hailea/product2/E20000.htm

to throw spanner in the works, for a godo price, basically same as the sun suns,

but with better warranty, spare parts and impeller as well as its sold by hollywood fish farm which means i have peace of mind

i was thinking of this,

it woudl not only future proof my return pump requirements, but it would is good wattage.

i would have to put a bypass valve before it goes to the outlets to feed back into sump if flow is too great.