Need advice on switching UGF/Crushed Coral to LS

[nickbuol]

OK. We have a 3" crushed coral "bed" in our 75 gallon. We have 80 pounds of live rock as well. Anyway, the tank has been doing well until about a month ago when the Nitrates started climbing. I was warned about this with a UGF about 3 months after the tank was set up (thanks LFS for selling me a UGF). Anyway, I have 100 pounds of southdown play sand, and 60 pounds of Arag-Alive from CaribSea. I called the 800 number on the back of the Arag-Alive bag to ask a question about the product, and talked to the guy for a while. He said to be cautious about swapping all of the crushed coral out at once as the ammonia would probably spike.
Yikes! That is not what I had been hearing around here. I was told to take it all out, save as many critters from the crushed coral as possible, put in the southdown, put the Arag-Alive on top, and put the critters in and let them dig into the sand.
How can I do this without having to worry much about my fish and corals?
I have a few thoughts, they are as follows:
I was thinking about putting that Southdown into a large tub with some water from my tank, and take some of the crushed coral out of the tank and mix it all up. The bacteria should start moving over to the sand in time. I still have to figure out how long it will take. I would rig up a heater, powerhead, and a light (for the photosynthesis bacteria). I figure if I can seed 100 pounds of Southdown sand, and add in 60 pounds of Arag-Alive sand in a 75 gallon tank, I should be OK in the long run.
My other idea was to take out ½ of my under gravel filter (it is in 2 plates, a right and left side), put some Southdown on that side, and cover it with a light layer of crushed coral, then in a few weeks do the other side, and in the end add in the Arag-Alive.
What thoughts do all of you have? If I tried to "seed" the southdown sand in a tub, how long do you think it would take for it to be "alive"?

 

[fixitdude2001]

I have heard of some doing the half know and then the rest later. We did a hole change . Whent and got as many plastic tubs that we needed and started syphoning water into tubs and then as the water started rising put in lr and corals and fish. do not syphone the very bottom tho. then all gravel was scooped out and the wet dry vac sucked out the rest. For all the live sand you have you should be ok most only seed with 10% live to 90% southdown, you are way over the 10%. We did have a small cycle but nothing dangerous everything came back just fine in our 72 reef.I did get scarred but the tank is much happier now. For saving the copepods and other critters you wont believe how fast they come back so many of them will stay with your live rock, just make sure you keep the temp up and good aeration in the tubs while you clean out the cc It took us about 3-4 hours from start to finish. Tank is doing awsume..cya...fixit

 

[mr . salty]

Just aggreing with what fixit said.With all the rock,and the ammount of Live vs dry sand you are using,you should have no recycle.I also agree that draining the tank is the best way to do this.That will keep the water from clouding when you remove the UGF,and CC...

 

[andymi]

Personally from using Arag-Alive on another tank I think you will see a spike. I am a big believer in Carib-Sea products but was not fond of the arag-alive product. I much prefer the natures ocean bio sand or going to a good LFS and buying sand from one of their tanks. I swapped out sand for a new plenum with new sand and I did not cycle, but I seeded with sand from an LFS and I have a 90 gallon. I left 1/4 of the water in the bottom of the tank and kept the fish and inverts and LR in rubbermaid containers for 4 days and nothing died. You can always keep the fish and inverts in the rubbermaids and put the LR back in the tank to have it do a quick cycle if anything. This might save you some headache, just keep an eye on the levels for a couple of days.
--Andy

 

[nickbuol]

How do the critters get out of the stockings? Aren't the holes too small? We have some small starfish (some the size of a dime, others the size of a quarter from one arm tip to the farthest) too...

 

[mr . salty]

It will be nearly immpossible to try to pick all these critters out of the cc..You could get a cheap 10gallon tank,put the CC in there,,And then pick out the critters as you see them...That is basically what I did,,but I ended up leaving the 10 gallon setup.It is now a seahorse tank...

 

[nickbuol]

OK. Here is what I am doing...
I've put the southdown sand into a large plastic tub . I've put enough water in there to allow a heater to work. I have also put in a bubbler, and a powerhead for movement. I then put in a few nylon balls with some crushed coral from the main tank in there. I figure that this will help to "pre-seed" the non-live sand a bit. Friday I am going to get some new live rock from the LFS and put it in the tub (30 pounds) which will eventually end up in the main tank for a few months until after Christmas when my wife gets her seahorse tank for Christmas. I am also going to get some of the "sludge" from the bottom of my LFS "curing tank." I have heard that this too will help to seed regular sand. After all of this sits in the tub for a week or so, I am going to do the swap, and mix the 60 pounds of Arag-Alive into the top .5 inch or so of my "seeded" sand.
Does THIS make sense, or should I not worry about pre-seeding the sand since it will be hard to know what part of the sand has bacteria and what part doesn't and I should just seed it when I put it into the tank and use the nylons still?
I have an OK way of capturing some of the critters in the crushed coral, so I will save a few of them hopefully along the way.
Let me know your thoughts....

 

[mr . salty]

That actually sound like a getter plan.Soaking the southdown is needed anyways so that it sinks to the bottom of the tank.Otherwise it will float,and cause a terrible clod in the tank.Preseeding it is also not a bad idea,and adding the new rock is also a good idea.Just to be safe if this new rock is not cured.If the water starts to stink after the rock is added,you may need to push your plan back a couple weeks for the rock to cure...Keep us updated on your progress.

 

[nickbuol]

Whew... I finally have a good plan for this. Thanks for the support Mr. Salty!
The live rock sites for 2 weeks in a curing tank at the LFS, and then goes into a live rock "display" tank with their corals... It should be pretty good. I got some there when we first set up the tank, and it worked great with no ammonia from die off. Of course, it helps that I live 10 minutes from the LFS door to my door....