View Full Version : converting a undergravel filter to a DSB

02/11/2006, 06:22 PM
I have been planning to convert my undergravel filter to a DSB. has any one on here done this. I was thinking of removeing my live rock. vacuming the sand bed out good. adding a few more inches of argonite pulling out the riser tubes but leaving the powerheads in the top or the aquarium for circulation. then putting the live rock back in. will this work? will the system have to cycle all over again?

02/12/2006, 07:01 AM
Once you disturb a sand bed, there is a very good chance that your tank will go through a noticable cycle. If you're pulling out old UG filter plates, there will be a ton of crap released into your water column.

02/12/2006, 11:20 AM
I am leaving the filter plates in as a plenum. I hope this works. the live rock I will put in buckets to perserve the biological filtering they provide. I am hopeing to have the system up to normal again in less than one week. I guess I will have to watch it carefully for cycleing before I put my fish back in.

02/15/2006, 01:29 PM
I did this on my mom's 55gal. This is what we did and it worked out great.

The Powerheads had been on the undergravel tubes for about three months and she had about 3" of sand. We added 3-4 more inches of sand on top of the existing layer only stirring in the top 1 or 2 inches of the existing sand bed. After the sand was added all livestock was added that had been removed. She left the powerheads on (connected to UG) for one more week. Then the tubes were pulled and the holes were covered up with sand. The powerheads remained in the tank for circulation.

During this entire process she checked her levels twice a day for the first week and once a day for the next month and now she is back to checking once a week.

All levels remained at 0 for the first 4 weeks. Then into the 4th week her Nitrites were detectable but barely. As far as I can tell the only cycle that the tank went through again was a slight bump in Nitrites but this was only for 2 days and seemed to have little/no effect on the wildlife (a few SPS's a few LPS's a few softies and a few fish).

Since this change her tank has been running great and all levels are perfect. She used a Live Aragonite/ Sand mix (don't know if it really matters). She loves not coming home to find a powerhead clogged with sand!!

If you have any more specific questions I will be happy to share our experiences with this.

02/15/2006, 01:30 PM
As far as putting your fish back in I would do it as soon as possible. We never took the fish out of the aquarium during this whole process. They are all still alive today!

02/15/2006, 01:50 PM
I did this two years ago with my 75G. I moved all my rock and fish into rubber tubs. Saved as much water as possible. Saved some CC and placed it in pieces of stockings. Then emptied the tank of water and CC. Washed it out. Had it drilled. Plumbed in a sump added a 4" DSB. Added my LR. Placed the bags of CC on the sand bed. Added Some New Water. Added the fish. Added the old water. Topped off the rest. Took the whole weekend, but by 10PM sunday, my fish were back in their tank. Was a little cloudy for a day or to from the fine sand that was disturbed. All the fish came through and my tank did not go through another cycle. I guess in the end, My LR was filtering more than the UG filter.

02/15/2006, 05:32 PM
thanks guys that makes me a little more comfortable about doing this. I was wanting to get my fish back in asap but was concerned about the cycling. sounds like things should go ok.