cabin
08/08/2004, 07:21 PM
Installing a new, mud-based substrate refugium/sump on an existing aquarium takes planning and a little nerve, but I’m happy to report that this weekend, we appear to have successfully pulled it off. The old refugium is now running along with the new. We’ll leave it like that for a few weeks, then gradually remove the old until the new one is handling it all. We’ll have to put up with a strange-looking obstacle in the living room in the meantime.
I decided to get rid of the old refugium because it felt like an accident (of the wet kind) waiting to happen, and because I wanted to be able to observe the life of the refugium through a clear-sided container. Since I was doing this anyway, I also decided to try a mud substrate, as I had read so many positive reports on using mud.
We bought a 30 gallon (12x36x16) glass tank to house the new goodies. Using plexiglas and silicon, we glued panels to divide the tank into (pictured, left to right) an input chamber, refugium (with 2 low strips to stabilize the mud), output chamber, and sump. The water enters the input chamber by tubes from the tank, moves from the input chamber through a slot about halfway down the divider, flows throught the refugium, leaves there by overflow, then goes through a slot at the bottom of the last divider to the sump, and finally gets pumped to the tank. (The plans for this came from Ecosystem, whose mud we were using.)
http://reefcentral.com/gallery/data/500/57927refugium_rebuild_low-med.jpg
I wrote down 16 steps for the day of the conversion, and forgot a few, but it helped having a plan. Previous to the move, I made up an extra 20 gallons of salt water, and bought some additional PVC pipe and elbows for the extra distance the various pipes would have to temporarily travel.
We estimated the tank system would be down for no more than an hour, but it turned out to be 2 hours. We pumped out the old refugium to within an inch or two of the substrate (enough to be able to lift it), emptied the sump totally, pulled out the sump and old refugium, and placed the new tank in their place.
We poured in the mud (20 lbs made about 1� deep bed, probably a little less than it should be). Using a plate to keep the mud from getting stirred up, we added salt water to the mud chamber. While that was settling, I cleaned the pump impeller (it had been in use 6 months, it was time anyway) and we plumbed the pump in its new spot.
The plan called for bio-balls in the chamber that receives the tank water and the one that takes the refugium overflow. The purpose is not to provide a home for bacteria as is usual with bio-balls, but rather to prevent algae and detritus from moving out of these areas into the refugium or pump. I’ve never bought bio-balls before, but apparently I got the wrong size, because they were so small (about ¾�) they could go under the plexiglas divider. Later we discovered that wouldn’t be a problem, because they float, but they floated out of where they belong whenever the pump stopped. I solved that by putting chaetomorpha algae across the top of them to hold them in place. While that seems to be working, and I think the algae will like the constant flow over the top of it, I do wonder how this is supposed to work. It seems like even with bigger balls, they would still float. I have never actually seen the manufacturer’s version, I am working totally from pictures and diagrams.
I poured the remaining water from the old sump through a net to catch any stray amphipods that were there and return them to the new system. We initially by-passed the new refugium entirely while the mud continued to settle, and plumbed the overflow from the tank into the old refugium, which was elevated and sticking out into the living room so that it could drain into the new sump section. The tank has two overflow hoses, so after an hour, we let one hose go into the new refugium to add it to the system. The next morning, we spent another hour and replumbed again so the entire outflow from the old refugium goes to the input chamber for the new. We’ll gradually remove the old refugium from the mix over a period of weeks. When it is all the way disconnected, I’ll have to do something to try to gather amphipods from the old sand substrate, not sure what, yet.
One fish (the chalk basslet) decided to jump out before we even got started (he must have seen all those water containers and decided he’d go live in a different one!). Fortunately, we noticed him lying on the rug before any harm was done. During the process, the fishes suffered through a lot of air bubbles until we got the pump flowing correctly, and inevitable cloudy water, but seem none the worse for wear. The bubbles problem was solved in minutes, the cloudiness was gone in a few hours.
Overall, I’m very pleased with the new system. I was able to turn the pump (Magnum 18) up to full flow for the first time. It is quieter, much tidier, there is more room in the cabinet (or will be, when the old refugium is not an obstacle), and I can SEE to observe the macroalgae and the critters living among it. I’ll let you know in 6 months or so whether I notice other improvements from switching to mud substrate in the refugium.
I decided to get rid of the old refugium because it felt like an accident (of the wet kind) waiting to happen, and because I wanted to be able to observe the life of the refugium through a clear-sided container. Since I was doing this anyway, I also decided to try a mud substrate, as I had read so many positive reports on using mud.
We bought a 30 gallon (12x36x16) glass tank to house the new goodies. Using plexiglas and silicon, we glued panels to divide the tank into (pictured, left to right) an input chamber, refugium (with 2 low strips to stabilize the mud), output chamber, and sump. The water enters the input chamber by tubes from the tank, moves from the input chamber through a slot about halfway down the divider, flows throught the refugium, leaves there by overflow, then goes through a slot at the bottom of the last divider to the sump, and finally gets pumped to the tank. (The plans for this came from Ecosystem, whose mud we were using.)
http://reefcentral.com/gallery/data/500/57927refugium_rebuild_low-med.jpg
I wrote down 16 steps for the day of the conversion, and forgot a few, but it helped having a plan. Previous to the move, I made up an extra 20 gallons of salt water, and bought some additional PVC pipe and elbows for the extra distance the various pipes would have to temporarily travel.
We estimated the tank system would be down for no more than an hour, but it turned out to be 2 hours. We pumped out the old refugium to within an inch or two of the substrate (enough to be able to lift it), emptied the sump totally, pulled out the sump and old refugium, and placed the new tank in their place.
We poured in the mud (20 lbs made about 1� deep bed, probably a little less than it should be). Using a plate to keep the mud from getting stirred up, we added salt water to the mud chamber. While that was settling, I cleaned the pump impeller (it had been in use 6 months, it was time anyway) and we plumbed the pump in its new spot.
The plan called for bio-balls in the chamber that receives the tank water and the one that takes the refugium overflow. The purpose is not to provide a home for bacteria as is usual with bio-balls, but rather to prevent algae and detritus from moving out of these areas into the refugium or pump. I’ve never bought bio-balls before, but apparently I got the wrong size, because they were so small (about ¾�) they could go under the plexiglas divider. Later we discovered that wouldn’t be a problem, because they float, but they floated out of where they belong whenever the pump stopped. I solved that by putting chaetomorpha algae across the top of them to hold them in place. While that seems to be working, and I think the algae will like the constant flow over the top of it, I do wonder how this is supposed to work. It seems like even with bigger balls, they would still float. I have never actually seen the manufacturer’s version, I am working totally from pictures and diagrams.
I poured the remaining water from the old sump through a net to catch any stray amphipods that were there and return them to the new system. We initially by-passed the new refugium entirely while the mud continued to settle, and plumbed the overflow from the tank into the old refugium, which was elevated and sticking out into the living room so that it could drain into the new sump section. The tank has two overflow hoses, so after an hour, we let one hose go into the new refugium to add it to the system. The next morning, we spent another hour and replumbed again so the entire outflow from the old refugium goes to the input chamber for the new. We’ll gradually remove the old refugium from the mix over a period of weeks. When it is all the way disconnected, I’ll have to do something to try to gather amphipods from the old sand substrate, not sure what, yet.
One fish (the chalk basslet) decided to jump out before we even got started (he must have seen all those water containers and decided he’d go live in a different one!). Fortunately, we noticed him lying on the rug before any harm was done. During the process, the fishes suffered through a lot of air bubbles until we got the pump flowing correctly, and inevitable cloudy water, but seem none the worse for wear. The bubbles problem was solved in minutes, the cloudiness was gone in a few hours.
Overall, I’m very pleased with the new system. I was able to turn the pump (Magnum 18) up to full flow for the first time. It is quieter, much tidier, there is more room in the cabinet (or will be, when the old refugium is not an obstacle), and I can SEE to observe the macroalgae and the critters living among it. I’ll let you know in 6 months or so whether I notice other improvements from switching to mud substrate in the refugium.