ok that said the guy on that site
That would be me
makes the media capacity of the fx5 much greater . in my eyes thats just the same as puting them inline with only the second pump on . you are just increasing the potential media capacity .
Its not the same at all.
First with the Fx5 modded you increase the cross sectional surface area for mechanical filtration, meaning you can use fine particle filtration pads for over a month without them clogging.
Second, you are reducing the flow velocity through the media for better contact.
Third, you are reducing restriction caused by the media.
Running two or three Fx5s on one pump, you are increasing the restriction.
2 or 3 Fx5s daisy chained will not allow the 2nd filter to capture much in the foam pads. The third Fx5 you would never ever have to clean so its only use would be 5 liters of bio media if its not modded.
3 Fx5s equal 1800 GPH with 15 liters of bio media.
yeah it will restrict the flow a little more but i shouldnt think so much that it would cause a problem.
3 daisy chained fx5s would be less than 600 GPH and 15 liters of bio media. I say less than 600 GPH because of the additional restrictions.
I am pretty sure it would be around 500 GPH but that would be interesting to find out.
I say do it for the hell of it. Remove the impeller in the first and second Fx5s and link them together and let us know what happends.
zenzo said that the impellor will be fine regardless of the load it would only be the flow output that would be affected
Yes the impeller would not be affected. But, why would you not mind a reduced flow? You already have 3 Fx5s running seporatly which is the best thing you can do. Why tie two of them together to cut the flow more than half?
also by running two filters like this there is the potential to reduce the nitrate level of the water .
Don't bet on that to much.