Changing To RUGF

> From: Williamson, Stuart <SWilliam at vccdocs9_telecom.com.au>
> Subject: UGF -> RUGF ?
> <snip bit about lights>

> I currently have an Eheim 2213 canister filter plus a UGF.
> An Eheim brochure suggests using it to drive the UGF as RUGF for
> luxuriant plant growth! I suspect overstatement, but given that I
> have the UGF and don't want to rip it out, am I better switching to
> the reverse filtration?  Will there be problems with an existing
> set up switching directions?
> One reason I think it may be better is that with more plants it will
> be harder to vacuum the gravel, but with RUGF this may be less
> important.  Finally, on RUGF, what flow rate is required.  I have
> read a number of sources that indicate it shouldn't be very high,
> but I can't locate any suggested rates.  I assume the canister filter
> would have more than enough throughput to drive two uplifts?


I keep a planted tank which uses RUGF and can recommend it as a
suitable 'lo-tech' set-up. 

1. There should be no problem in switching from UGF to RUGF.

2. I still vacuum very occassionally on the small areas of gravel where
   there are no plants yet (about 20%) of the bottom and I just leave 
   untouched the majority of the gravel surface where there are plants.

3. I can't remember exactly but I think you need to turn round the volume
   of the tank about 3 to 4 times per hour. (?)

> From: Mike Variano <mvariano at vnet_ibm.com>
> Subject: RE: UGF---RUGF??
> Stuart, leave the UGF in. Just don't use it. Stop the flow,
> Vacuum every inch of gravel till is very clean. Clean under
> the plate if possible. I used a small hose, alternitly
> drawing and blowing water. I also shortened the lift tubes
> just the hide them.  <snip>
I would not recommend turning off your UGF if it has been running for
some time because it will be supporting a bed of aerobic bacteria
which will die when the water stops circulating. For this reason I would
also recommend completing the change from UGF to RUGF all in the same day.