Filtration Rate

[DaveA76]

can someone advise me,what is the minimum and maximum turnover rate in lph i should aim for on a 240l and a 650l tropical tanks stocked with south american cichlids and plecs

 

[RRaquariums]

With cichlids I always try to get 10 times per hour turn over you can go with less but I've found anything under 7 times per hour turn over is to little so somewhere in that area is good.

 

[DaveA76]

thats great thanks, running at manufacturer specs 3000lph on the 240 and 9000 lph on the 650l. running multiple filters on both which i presume is handy incase one goes down, right ?

 

[RRaquariums]

Yes two smaller filters to get your desired turn over is best in case one goes down

 

[ShinySideUp]

I have one Fluval FX5 running on a six foot, 640 litre tank. I have recently added an internal Fluval U4 to clean out little bits (see another thread).
 
Despite these 7-10 x turnover rates people talk of  I find it difficult to reconcile with a tropical tank that may have slow-moving, peaceful fish in it. A ten times flow for a 640 litre tank is 6400 litres per hour and this equates to a flow rate through the pipes of about 12 kilometres an hour so this is also the speed at which water would be coming out into the tank. That's the speed of a human running at a healthy pace, how many fish want that sort of flow rate if they get near the exit (or the outlet pipe to the filter more importantly)?
 
My filter turns over about 2500 litres per hour, probably less since that's the rated pump speed without filter material and everything has been running fine for nearly a year now.
 
My old 240 litre tank ran with a Fluval 305 which was 1000 litres per hour, say 600 loaded so again we are looking at 3 to 4 times tank capacity.
 
The supplied filter with my very old Juwel 120 litre had a 600 litre per hour (say 400 loaded) so again we have 3 to 4 times turnover.
 
So for a tropical tank, planted with peaceful fish, you need no more than a loaded filter that will change your tank contents four times an hour.
 
Others may heartily disgree with me but I have kept fish for fifteen years with a minimum of deaths with the above turnover rates; judge for yourself.

 

[fishwarrior]

On a 75 gallon, I have almost 1400 gallons per hour flowing through it, about 18x turnover.  I position the return and powerhead so that they point at the glass, less disturbance and breaks up the tidal wave.  I agree on the 10x is plenty of flow.

 

[ShinySideUp]

On a 75 gallon, I have almost 1400 gallons per hour flowing through it, about 18x turnover.  I position the return and powerhead so that they point at the glass, less disturbance and breaks up the tidal wave.  I agree on the 10x is plenty of flow.

 
18 times !? Why? I'm surprised your filter media can hang on to the bacteria, it's like jet washing!

 

[fishwarrior]

 

On a 75 gallon, I have almost 1400 gallons per hour flowing through it, about 18x turnover.  I position the return and powerhead so that they point at the glass, less disturbance and breaks up the tidal wave.  I agree on the 10x is plenty of flow.

 
18 times !? Why? I'm surprised your filter media can hang on to the bacteria, it's like jet washing!
 

 
No reason other than I ended up with a strong mag drive pump, definitely overkill on this size tank but it keeps it clean and I have a very strong biological.  My upcoming plywood build I plan on not over doing it.  Bare minimum is really all you need, make  use of powerheads too.