Mistake undergravel filter

[merman]

I started my tank 2 years ago. I read and read and heard 20 different ways to setup a tank. Well, I made a mistake. I put a undergravel filter on the bottom. So, I got 20lbs LS, and 30lbs LR on top of the filter. I want to take it out though. I don't think it's a good thing to have it there. So... if I take out the rocks and corals and fish, pull out that filter, should it be safe to put my corals/fish back in? Or, will this be a huge shock/cycle for my tank? Letting loose toxic gas and stuff from under the filter.

 

[playtime]

I have an UGF and so far no problems. That said, It should be fine to remove it then add your stuff back. What I did was syphen out the cc first to remove most of the yuk then removed everything including the filter. You shouldn't have to take out all the cc just remove enough of it to get to the filter, otherwise you might have a huge mess. I wouldn't remove all the water either. Your inhabitants should be fine, I would keep the lights off after due to the shock to the fish and corals. you don't want to stress them out any more than you have to. Hope this helps
Playtime

 

[sonny]

The u/g filter is not really doing much at all with sand on top of it. I suggest you disconnect the lift tubes and cover it over with sand/gravel. Watch your levels carefully. You will in effect have a plenum, but the problem with it is there will not be enough diffusion through the u/g plate to effectively denitrify the water. Watch your levels carefully and if they don't fluctuate much, let it stay. If you want to upgrade to a larger tank, or if you move the tank, then you could remove the plate. If it's not a big deal to you to remove everything, you would be able to put the corals back in immediately. Siphon some water off into a bucket and remove the corals from the tank, then siphon the rest of the water off and put the live rock in there. Remove the u/g plate, then start re-stacking the rock. Let the water clear some before adding the coral back. I would definately use this time to do a heavy water change. Make sure your ph and salt level are the same before reintroducing the corals. You may have a spike of ammonia and/or nitrite after such a change, but the tank should rebound in just a few days.
Sonny

 

[mr . salty]

I agree with Sonny on this one.If the levels are not out of this world high,leave it in for now. If you must remove it,I would syphon almost all the water out of the tank.Then remove the CC and UGF.By getting most of the water out first,you only contaminate a couple gallons of tank water.Clean the bottom of the tank,and start refilling it..I would also HIGHLY RECCOMEND switching to a deep "live sand" bed at this time..After all that work,why would you want to put the old dirty CC back in??? I wouldn't..Plus the DSB is benafitial too your tank...CC is not..

 

[merman]

Thanks for the info gang. I only have 2" of sand right now, and cc on one side of the tank. Looks like I'll take out the cc and move up to to a deeper sand bed. Thanks again.

 

[andymi]

I have to disagree about the sand levels. I think it really depends on the particle size of the sand on top of the UGF. I and many others that I know of use CaribSea special grade and have and have used UGF's for years with no problems. Many of the systems have 3-4"s of sand on the bottom and they filter extremely well. Granted this is pretty deep, but it does work and work well.
--Andy