Thanks Mick and Mark the input is invaluable. I now see that separate inlets and outlets makes a lot more sense and I now intend to go this route.
I'll probably get used to the sight of the extra pipework and not notice it after a while
and I already have a couple of ideas of placements and how it might improve rather than degrade the flow pattern. I quite enjoyed experimenting with my single inlet and outlet for some time before I settled on the current position... two sets should keep me amused for ages
So my next choice is which pump to go for...
After a fair bit of research I have opted for the Eheim Compact range. This was done by weighing up price and wattage consumption against rated flow. (
http://www.charterhouse-aquatics.co.uk/ ... 4_137.html )
Now I just need to pick which one... 1000, 2000, or 3000lph.
My tank is 160L and my Tetratec is rated at 1200lph. The filter has the reactor and the heater inline. I haven't done tests to see what the acutal flow of the filter is.
When it is filled with media, and just been cleaned the filter has sufficient flow to power the venturi loop on my reactor. But I know it is only just enough as after a few days the reactor venturi loop becomes inactive. This is not a problem as such as the reactor never reaches its capacity. However the venturi works great as an 'automated bleed valve' so it is something I would like to address.
So I was thinking about going for the 2,000lph Eheim and having the reactor hooked up inline with it. (Leaving the heater on the filter loop.) This would give me a theoretical 3,2000lph flow\20x turnover.
1000lph seems a bit low to be confident that the venturi will kick in.
3000lph might be a tidal wave in the tank, or would it? (the 3000lph consumes a noticeable amount more electricity as well.)
How does that sound to you guys? Any comments you have got are appreciated.
Incidentally, putting the Eheim on a timer so that it only comes on with the CO2 is a possibility I like the idea of. Will be nice to give the fish a rest.