Going to swap tank for tank - any advice?

[kurt_n]

Guess it's my time to ask for advice, versus giving it.

I've got a 7+ year old 46g bowfront, no sump. Very well established, original fish, large coral colonies. But the center brace has a hairline crack in it where it joins the rest of the frame, in the back. Not sure how long it's been there - could be new this week, or been there for years. I just changed my lighting and that back area of the tank became more visible. Anyway... I'm not happy with that and neither is the wife. So we're going to replace it with an identical 46g - just going to swap tank for tank, with no changes.

Here's my plan so far. Tell me if I'm missing something.

a. Get new tank, paint back like old one, and do a water test in the garage.

b. Before that, set up quarantine tank, and transfer fish (one each o.clown, bangaii cardinal, blue-green chromis, little yellow clown goby and a cleaner shrimp) just before tearing down existing tank.

c. Siphon tank water into brute trash can (for tall rock pieces with corals encrusted to them) and a smaller tub (for smaller rock pieces) and put rock into tubs.

d. Scoop old sand out of tank (DSB) and throw away... maybe keep a few cups to seed the new sand with some critters.

e. Take old tank off stand, put new tank on stand, and start pumping water from brute trash cans into tank, filling tank about half way.

f. Put rock work back in place, and put in NEW sand. Top off tank with rest of old water... or maybe half new - might as well do a water change!

g. Put fish back in.

A few questions...

1. I'm using the same rock I've had for 7 years, but using new sand (not "live" sand, but just plain ol' dry sand.) Should I expect a mini-cycle?

2. The only reason I'm using a QT for the fish, versus just putting them in a tub for an hour or so, is in case something goes wrong during the transfer, and I can't put them back in immediately. (If I should expect a mini-cycle, I know they shouldn't go in anyways.) But do you think those fish (clown, chromis, cardinal, and yellow clown goby) would be good in a 10g for a short while? Or should I split them up and put them in (2) separate 10g tanks? I've got two... just not sure if it's required for hopefully a short time.

3. What am I missing? Have you done this and wish you'd done something differently?

I'm not looking forward to this. But I also don't like the ticking time bomb I might have in my living room!

 

[Windirmere]

I just switched from biocube to a 57g no cycle all dry rock in the DT all the biocubes LR in the sump, No coral loss. Main things that saved me were, Start early took about 6 hours : \ Have extra SW mixed and heated. Wet test your plumbing! I had a leaky bulk head scare that was 100% avoidable. Only fish that seamed phased was my Yellow Corris wrasse i though he jumped out or got sucked down into the sump. It turns out hes just a chicken and was hiding in the new sand. Plan everything, Make a list of step by step with estimated times, have lots of towels on hand!

*edit All new sand as well, didnt want to stir the sand in the biocube.

 

[hijinks]

One thing you might have issues with based on how many fish you have is you are removing your sand so you are losing a ton of the bacteria population that has built up to break down the ammonia in the tank.

If I were you, I'd have lots of extra salt water mixed to do big water changes if you see the ammonia get high.

Other then that the plan seems good to me

 

[JKDMan]

Dude. just get a horse trough from harbor freight of appropriate size. Put all your water sand rocks livestock in there with a heater and a powerhead. Then switch tanks and put it all back. Easy
Im about to do the same thing because im switching out the stand on my 210. It has the shitty all glass pine stand and it worries me. Also not enough room under there.

 

[kurt_n]

Thanks for the replies.

Regarding losing the bacterial population in the sand... yeah, I was a bit concerned about that. I was originally thinking along the line of what JKDMan mentioned, but after talking to a few others that have done this, they mentioned that they saw a mini-cycle... even using their original established rock and new sand. They suggested having the fish in a QT right off the bat so I could let things sit for a couple days and check the ammonia levels, versus having to scramble at the last minute to get the fish back out.

It's only 3 fish of any size (clown, cardinal, chromis) in a 46g, so the bioload is pretty small, but yeah... I always have 20g of heated saltwater onhand, and I was planning on having 40g onhand when I do this - in addition to the tank water that was in the tank to start with.

Do folks think those 3 fish (clown, cardinal, chromis), a little yellow clown goby, and a cleaner shrimp will get along OK in a 10g for a few days? They've been together in the 46g for years and I've never seen any aggression among them.

 

[anbosu]

Yes I think they will be ok in a 10g for a few days. I would get one of those ammonia alert badges just in case you have water quality issues in that tank.

I would also consider adding the sand to the new tank prior to putting the rock back in.

It looks like you have a solid plan overall though.

 

[ReeferBill]

What about new live sand? +1on anbosu when to add sand and place some rock in first on bottom glass so you do not have any rock slides!

 

[kurt_n]

Yup... a little sand goes in first, but my rocks sit on the glass so nothing can undermine it. It's the same way I set it up about 7 years ago. Now you got me thinking though, along with what anbosu said.

When I originally set it up, the tank was almost full of water. I was cycling a little before having the live rock delivered. Then the rock went in and the sand afterward.

But in this case, no reason to have the water in there. I can put a fair amount of my new rinsed sand in there, and push it off to the sides where my rockwork isn't to still enable me to put the rocks on the bottom glass. I can then fill the tank about halfway with water, and be able to minimize the sandstorm for the most part. Add the rock and push the sand up around the base of the "towers", then add more sand and top off the tank.

Most of my coral is encrusted quite nicely on my rockwork, and it's covered in pretty nice looking coraline algae, so I want to minimize how long its out of the water.

 

[anbosu]

That sounds like a solid plan.

 

[kurt_n]

Here's a shot of the tank from a year ago. Hopefully I can get the rock work back in its original position and my fish don't hate me too much for a few days stay in their temporary little 10g home!

 

[thegrun]

I've done the switch several times without a problem. You will not have a new cycle assuming you keep the rock wet to prevent die-off. I would expect some mild diatom blooms early on with the new sand, but not nearly as bad as when you first set up a tank. Have you considered simply replacing the brace? You and use a pipe clamp to temporarily pull the tank back together while the new brace is installed. If you tank is acrylic you can remove the clamp after 24 hours. If it is glass you would have to live with the clamp for two weeks, but either way you would save yourself a lot of work and money. If this is just a good way to get a new tank, then proceed as planned! Expect it to be a long day, these transfers always take me twice as long as I would expect. Good luck!

 

[kurt_n]

Just figured I'd post an update and "lessons learned" in case anyone comes across this down the road and is looking for advice.

I swapped out the tank a week and a half ago, and all is well. Been checking for ammonia and nitrites, but haven't detected any, so it appears I'm not going to get a mini-cycle even with replacing all the sand. I was able to get all the rock work back in place pretty much like it was before. I didn't remember how interlocked things were under the sand bed, and where the epoxy "joints" were between rocks, so the reassembly was... interesting. Many choice words were used.

A few things that didn't go according to "the plan".

1. I didn't suck out all the water before I started moving rock and the minute I started pulling rocks out, I had one major sandstorm. I'd intended to reuse most of the water and also use it in the tubs I was using to house the rock while I swapped out the tanks.

Forgot to mention in my original post that I had a quasi-deep sand bed... probably about 4-5 inches thick. So when the rocks started coming out from under the sand, the water got really nasty, really quick. It didn't stink or smell... just that normal cloudiness from the detrius. So I should've pumped *all* the water out before messing with the rock work.

2. One of the pieces of rock (the right-most "tower" in the picture above) had more buried under the sandbed than I remembered. Once I got the entire rock out of the tank, it didn't fit in the tubs I had ready. ACK!!

Luckily, it just *barely* fit in one of the saltwater storage tubs I had in my garage with new saltwater, at temperature. So much for having pristine water in that tub for use in refilling the tank, but so it goes.

3. My old Oceanic tank sat perfectly on my Oceanic stand. The stand was leveled, and the old tank frame was perfectly level with the stand... so no need for foam or shims. I wasn't as lucky this time, and I didn't even think about the fact that I may need to deal with an unlevel frame.

Long story short... I've always been a "no styrofoam under the frame" person, but not now. I spent a lot of precious time trying to figure out how to shim the gaps with either composite shims or styrofoam. Ended up with the 1/2" foil-backed styrofoam under the tank which seemed to do the trick. I lost about 3 hours for not considering that possibility, with the trip to Home Depot and scouring the forums on the pros/cons of foam!

Those were the three big things that went a little sideways. Nothing too bad, but it was a long day. I started catching fish at about 8am (only took 45 minutes to get all four and a shrimp), and finally went to bed around 11pm after putting in just shy of 80 lbs of sand... and creating one heck of a sand storm!

My fish stayed in my 10g quarantine tank for 2 days while I let things settle down in the new tank and was going to keep them out for another day, but I started detecting a hint of ammonia in the 10g QT. So back into the display they went. It was funny to watch them all go back to *their* spots/corners. It was like nothing happened.

As a side note, my 4-5 inch sand bed was just shy of 8 years old. I was kind of curious what I was going to find when I scooped out all the old sand. I really wrestled with the whole DSB thing when I set the tank up and depending on what I found when I broke this tank down, I was ready to go away from it. But I have to say... that sand bed looked really really clean. No discolored spots of sand (once you got away from the glass) or bad nasty smells. I was really surprised at how clean the sand looked. There were a couple small fist-sized pieces of sand that had all bonded together, but other than that... nothing really bad.

Oh... and yes, I'm now having that lovely diatom bloom from the new sand. Hopefully it'll be over quick!