Changing CC to DSB

[oregonbud]

Hi everyone,
I currently have a 55 g FOWLR (and a couple inverts) that I am going to be wanting to change the CC to a DSB very soon (wish the LFS would have told me about the nitrate issue with CC) and I have seen numerous posts on this site about the best way to change the bed, I was thinking about removing all but about 1" or even .5" of the CC then placing the 3" DSB on top of that - is this a bad idea?
Also my tank seems to have finished its cycle(Ammonia .01, trites, .02 and trates about <10), adding live rock definitely helped, would adding sand (mix between southdown and live) start another cycle? If so would curing the live sand prior to adding it to the tank be a good idea? Right now I have 3 damsels, 6 turbo snails, and a couple scarlet hermits, so not a ton in the line of livestock, but don't want to kill anything because I did something wrong.
Thanks for all the great advice.

 

[buzz]

That cycle may not be so "mini." If you are going to do it, I would find a place to QT all of your fish during the transition.
I agree not to mix cc and sand. You should replace all of it. You may want to leave a mesh bag, or stocking full of CC in the tank for bio-filter purposes until the tank re-establishes.
But I would find a temporary home for your fish and inverts.
Others on this board found out the hard way that changing out substrate can be brutal on fish.

 

[pokke]

I agree, remove the CC. The reason is 2 part. First, the CC will eventually rise through the sand and rest on top. The second is that now the CC will be the same old nitrate trap it was before.
I went through the same discussion a few weeks ago. I couldn't get my tank to cycle properly with CC for whatever reason. Once the CC was gone and the DSB was in, I cycled in just over a week. Water parameters are solid and I think it looks better!
Good luck on however you choose to do this!

 

[buzz]

Right now I have 3 damsels, 6 turbo snails, and a couple scarlet hermits, so not a ton in the line of livestock, but don't want to kill anything because I did something wrong.
There may be plenty of bacteria on the rock. The CC may not have much to kick up...I just would hate to take a chance and have it backfire. I prefer to be a bit overcautious when it comes to things like this. But perhaps you're right...may not be a problem.
oregonbud....you're choice...

 

[oregonbud]

Thanks for the advice, maybe I should clarify - this is a newer tank, only about 10 weeks old at this point, the live rock (60 lbs) is from my lfs store, it was in their tanks and they said it has only been in the tank for about two months, but was cured by them before they placed it in their tanks.
I kinda figured replacing all the CC would be a good idea, as far as how much junk is already in the bed, i have already done two 25% water changes (nitrates were way high) and both times I vacummed the CC really well, it doesnt look like there is a lot of nasty stuff in it yet. Doing a mixture of the southdown with LS (I like the 80-20 mix suggested earlier) would the cycle that is created from replacing the substrate be severe enough to finish off the damsels I actually cycled the tank with?
The reason I really ask is because I do not have a QT tank set up yet (still trying to convince the other half that this hobby isnt "that expensive" ) so going out and buying another tank may not be the best thing to do at this point, i do however have a tubberware tub and protein skimmer, powerhead, heater to cure the sand in - should I just do that first to be on the safe side? Or is curing the amount of sand I will be placing really necessary for the size cycle I may or may not experience?
Sorry for any confusion I just want to make sure I dont buy any unnecessary things, or spend time doing something not really needed.
Also I know you guys hate these ID questions but I noticed a new critter on my LR yesterday and was wondering if anyone had any ideas as to what it could be - I tried to take a picture but it still is too small for my cheap digi to capture.
It is about 3/4" long and purple, at the top of it has a circular pattern of 6 or 7 little knobs that protrude out. The center of it has similar ones that I see moving occassionally, and is a lighter shade of purple, and the bottom of it is just a purple stub - any ideas? I have tried doing some searching and my best guesses are that it is a sponge or a soft coral maybe?

 

[pokke]

I don't think that changing the substrate will cause a new cycle. The new southdown sand is basically inert so that wouldn't cause it. The live sand being added will likely only contain bacteria and also shouldn't contribute to a cycle.
I've seen where others have moved the contents of the tank to one side, pulled out CC and replaced that side with sand. Then moved rock and such to the new sand side and clear the other.
If you are doing this, I'd try to minimize the sand storm as much as possible as described in the thread. Of course the best thing would be to relocate the livestock (leave the rock) if at all possible.

 

[oregonbud]

Whooo !!
Well I went ahead and changed the cc to a dsb yesterday, and am kicking myself for not originally setting it up that way. The tank looks 150% better (as far as realism goes), and everything in the tank seems to seem a bit happier (that could just be my optimism at this point tho) I wound up adding some more LR (about 25 lbs from a friends existing tank) at the same time as replacing the bed. So far so good, I checked all my levels this morning and noticed a slight amonnia rise(.03), and the nitrates seem a bit high (12) still but I am fairly sure that is left over gunk from the cc being stirred up so hopefully they will lower quickly.
Unfortunately I never did find southdown up here but I wound up getting 80lbs of playsand and seeded it with 30lbs of live.
So needless to say I am very happy with the results, and appreciate the replies to any of the questions I have and will ask
And on a even cooler side note - upon checking out my new LR this morning I noticed 2 very nice feather dusters, a crab of some type - I think its an anemone crab but not sure - and various other neat little things. I did find another one of the purple blob like things except this one is a bit bigger so I may be able to get a picture to see if anyone knows what it is - want to make sure its not young aptasia or anything equally pesty.

 

[crazy8]

Just for my knowledge, what kind of playsand did you find. I found some local stuff here myself (James River in VA) Looks better than anything in the store as far as color. I am probably going to change my substrate today, but I wanted to know if there is something to fear in a playsand?

 

[oregonbud]

Crazy8 -
I had the same problem here - it seemed like all the sand I found at the hardware stores was more of a crushed gravel then a sand - I actually went to my LFS and talked to the guys there, told them what I was wanting to do, and he recommended a beach play sand from monterey that he had left over from the last big tank they set up - it was a bit more then play sand at the hardware store by about 6 bucks per 50lbs (and I bought the last of it he had) - so I didnt mind spending the extra few dollars. From what I have read the best thing to do is look for aragonite based sand, rather then a silica sand - but you will find varying opinions on this.
If you have a good rapport with your LFS (meaning they don't try to force stuff you don't need, but offer good advice no matter how much you spend if any) I would say check with them. I spent about two weeks in my quest to find sand and found that sand is a strange thing as far as what areas have what types, and season seems to affect it as well, if you do some searches on here for southdown alternatives you will find some good reading material

 

[crazy8]

This is one of the things that kills me. The aragonite based sand is for biofiltration as far as I can tell. CC must do a pretty good job at that as well except that the size is so large air pockets cause a buildup of toxins from what I can tell. So why don't people mix the two? The a silica based sand wouldn't be a problem. Or maybe I am trying to make things too easy.

 

[oregonbud]

The reason you would not want to mix the two (CC and sand) is because the sand will sift through the CC so the CC will eventually wind up on top again, causing the nitrate issue that CC is notorious for, so I think the theory is that if the CC is on top of the DSB the benefits of the DSB would be lost because the CC effectively is acting as a barrier keeping the nitrates in the water, above the sand bed, and the good stuff from the sand is trapped below the cc thus losing its effectiveness.
I may be incorrect but I believe the bigger reason for the aragonite vs silica is for buffering purposes, I think if you seed the sand (arag or silica) with LS, it will be the same biofilter, from the start, however I think any type of DSB would eventually become LS seeding it just establishes the bacteria quicker, - but the buffering capabilities could be lost.

 

[crazy8]

Well, thanks for the help. I ended up clearing my CC today and put in sand. I am going to buy about 50-75 lbs of live rock and from that I will seed the sand. It will make it "live" before too long. May take a little longer, but I would rather waste the time now than later. I now have a 4-5 inch DSB with a realistic looking off white color. This will allow me to get a good cleaner crew going. I found a new LFS (not that local actually) where the guy really had some good setups and I love the snails that come up during feeding. I know I will be getting some of those.

 

[mvogel2]

how about putting the old live cc into the sump of a wet/dry filter...Would that help with filtration?
matt

 

[thomas712]

I think it would just wind up getting dirty in there and collecting sediments in which case it would wind up creating nitrates.
Thomas