Will Changing to Sand cause a cycle

[briandg]

I've posted a few questions about a tank I'm about to upgrade to and I have another one. I currently have an established 55 gal tank w/40 lbs of live sand. It is well established and the tank is full of pods. I am ugrading to an established 180 gal tank that I have yet to pic up. It has 310 lbs of live rock but had crushed coral instead of sand in it. I am going to change it out to sand. I want a sand bed of about 1.5 to 2 inches which is the depth of my current sand bed so I will need to add about 100 lbs of additional sand. My question is this:
1. Should I purchase 100 lbs of regular sand, then add my current sand to seed it.
2. Should I purchase more live sand.
3. Will either of these options cause another cycle in the 180 gal tank.
This is important because the tank comes with some fish, and my current tank is fully stocked.
I plan on temporarily putting all of the fish in my 55 and slowly moving them to the 180, as was suggested on this site. But I don't want to introduce the fish if the tank will again cycle. If it does cycle, I will have a major problem as my 55 will already be temporarily "WAY" overstocked.
Thanks
Brian

 

[sly]

You sound like you have a good plan. Because the tank is already established and has that much live rock you should be fine to swap out the substrate. The thing that causes a cycle is when you disturb the nitrobacter (anaerobic) bacteria by scooping out the substrate. You expose it to oxygen and it dies. Then you have no bacteria colony left to remove nitrates from your tank. Because you have so much live rock you already have this bacteria present and it is locked up safely in the rock. I doubt that you will have much of a nitrate spike.
However you may lose some aerobic bacteria temporarily. Aerobic consumes ammonia and nitrite. If you have a good established wet/dry then you should be fine. But if you don't then you need to closely monitor your ammon, nitri levels and keep them under control with water changes until your aerobic colony picks back up after the substrate change. Aerobic bacteria grows quickly and so if there is a spike, it may not last long.
If it were me I would buy a bag or two of live sand just to add some more biodiversity to your tank. It will reseed pods and other things that your sandbed may have lost over the years. I would use your existing sand but be sure to vacuum it first before you reuse it so that you remove any excess ditrius which may cause ammonia problems.
Move your fish slowly so that the 180 has time to grow with the bioload and closely monitor your ammonia and you should be fine.

 

[briandg]

Thanks for the reply, I forgot to mention, that I will also be adding 70 more pounds of live rock from my 55 so I'll have about 380 lbs of established live rock. Also, a stupid question.... How do I vacuum my sand. Finally, I think I've pretty much gotten it figured out. As far as adding fish to the new tank, I was thinking of moving 3 or 4 fish fairly quickly since she currently has 6 fish in the tank, so I'm thinking it could handle that bioload and maybe my 55 won't be quite so overstocked while moving. Does this make sense, or should I just add 1 at a time slowly. My concern is I will have a Sohal and Yellow tang along with a blenny, goby, 3 clowns, royal gramma, and two dwarf angels in my 55. Although I'm not sure yet if I will keep her dwarf angel, two in one tank makes me nervous, but previous posters said they should be fine in a 180.
My thought was to introduce the yellow, blenny and the smaller of the two angels to the 180 within a day or so of setup, then gradually move the rest.
Would this be a mistake.
Thanks

 

[sepulatian]

The thing that causes a cycle is when you disturb the nitrobacter (anaerobic) bacteria by scooping out the substrate. You expose it to oxygen and it dies. Then you have no bacteria colony left to remove nitrates from your tank. Because you have so much live rock you already have this bacteria present and it is locked up safely in the rock. I doubt that you will have much of a nitrate spike.
I am sorry, but I disagree with this part. I moved my tank. The sand was scooped out and sat cold in buckets for a week (covered in saltwater). I re-set up my tank with all of the same equipment, tried to spike the ammonia to be sure the bateria was still alive. It went to .50 and to zero within 2 days. I never removed the krill (ammonia source). And it just leveled out. This was with 35-40lbs of LR in a 55. (certanly not an over abundance of biolgical filtration)

 

[sly]

I'm not exactly sure what to say about putting the 4 fish in the 180. On one hand you don't want to add that much too quickly to a new tank but on the other hand you don't want a million fish in a 55 gal. Between the two I would probably put the fish in the 180 and keep a close eye on water parameters and do water changes as needed. It's important not to stress the fish too much. Constant movement and disturbing the tank is not good for them. You may want to leave your lights off a little more at first so that they will stay calm while you are moving things around. Keeping their stress low is very important.
As for the vacuum... Just use a simple gravel vacuum that is avaliable at any fish store. Lightly vacuum any dirt off the sand before you take it out of your old tank. Since you are going to be reusing it, you want it to be as clean as possible. Try not to suck up too much into the siphon hose while doing it...

 

[sly]

Originally Posted by sepulatian
I am sorry, but I disagree with this part. I moved my tank. The sand was scooped out and sat cold in buckets for a week (covered in saltwater). I re-set up my tank with all of the same equipment, tried to spike the ammonia to be sure the bateria was still alive. It went to .50 and to zero within 2 days. I never removed the krill (ammonia source). And it just leveled out. This was with 35-40lbs of LR in a 55. (certanly not an over abundance of biolgical filtration)
Nitrobacter has nothing to do with ammonia oxidation. You shouldn't have seen an amonia spike. If you read more carefully I am talking about anaerobic bacteria. This is the bacteria that reduces nitrate. People who have deep sand beds will kill this colony if they expose it to air and therefore they will have a sharp rise in nitrates. Disturbing the nitrobacter colony will not cause your ammonia to spike and that is not what I was talking about. I was refering to the bacteria that consumes nitrate.

 

[briandg]

Originally Posted by Sly
I'm not exactly sure what to say about putting the 4 fish in the 180. On one hand you don't want to add that much too quickly to a new tank but on the other hand you don't want a million fish in a 55 gal.
Yes that's my dilema . My thought process (and it could be wrong) is that her tank should already be able to handle this bioload because she currently has it stocked with more fish than this. It seems to me (again I could be wrong) that if I'm careful to keep the live rock in her water in the move, the tank should continue to handle this bioload. But I want to make sure. I just am afraid of both the stress and a crash of my 55 before I get all the fish moved over. I was planning on moving the rest over 1 a week maybe two for the smaller fish like the clowns. I kind of want to move the bigger fish first but I'm thinking the Sohal should go in last because of aggression. I want to move my blenny over fairly quickly because there won't be any or much live rock left in the 55 because I want to move as much over as possible to help prevent a cycle in the new tank. LOL I know I'm rambling, but my head is spinning from all of this and I want to get it right.
I also wanted to mention that my current sand bed is between 1.5 and 2 inches max.

 

[briandg]

One last thing I want to mention. I haven't tested her water yet, and won't pick up the tank for about a month. We are going to move our current tank and change the carpet. My wife wanted to do this in about a year, but I don't want to have to take down the tank after it's set up. Anyway I'm rambling again . I am going to test her water this weekend, but my hunch is that her nitrates out way high. She says she's been burned out on the tank and neglecting it, not doing water changes. She also uses tap water. She doesn't have many inverts left and only a couple of shrooms and polyps left. My guess is the rest have died because of nitrates. I'm planning on doing a huge water change when I get the tank, but I don't know how much I should do. Maybe I should wait and post this as a seperate question after I test her water. But I was thinking of putting about half her water in and filling the rest with RO water. Then a few days later doing another 25 to 30% water change and test the results. Does this sound logical, or is this too much. I'm worried about my inverts when I move the sand and rock over.
Thanks

 

[sly]

Your water change idea sounds good to me... just make sure you use premixed saltwater that is the same SG and temp as your tank and let it oxygenate (with powerhead or air bubbler) overnight before you do use the water for your water change.
Also be sure to acclimate your fish properly when you move them over to your new tank. Maybe someone else has some ideas... but what you've told me sounds pretty good.

 

[briandg]

Thanks, yeah I was planning on purchasing plenty of salt before the move, testing her salinity this weekend and having a couple of trash cans full of water ready when it's set up. I don't know if it all will work, but I can't think of a better idea. I don't know who's gonna be more stressed during the change, the fish or me

.

 

[sepulatian]

Originally Posted by Sly
Nitrobacter has nothing to do with ammonia oxidation. You shouldn't have seen an amonia spike. If you read more carefully I am talking about anaerobic bacteria. This is the bacteria that reduces nitrate. People who have deep sand beds will kill this colony if they expose it to air and therefore they will have a sharp rise in nitrates. Disturbing the nitrobacter colony will not cause your ammonia to spike and that is not what I was talking about. I was refering to the bacteria that consumes nitrate.
My apologies, I mis-read. You are correct.