Does Anyone Have Experience Switching Sand Substrates?

[tetraodon_biocellatus]

I currently have a 55 gallon that I need to seriously revaluate. It has horrible large pebble-blacksand mixed substrate currently and I am going to switch it with pool filter sand. (or PFS if youre trendy). I know I will likely have to move my cichlids into a holding container which I can do easily. But I am concerned about disturbing the biofilm/bacterial colony on the current substrate. I will be using the same rocks and driftwood for the hardscape and I am running a 400gph Aqueon QuietFlow and a 383 gph Fluval 406 Canister filter. They both have well established bacterial colonies. I do have relatively delicate species including bolivian rams rams, keyhole cichlids, and geophagus brasiliensis. I am especially concerned about the rams. Am I likely to see an ammonia or nitrite spike and if so how should I handle that with susceptible species?
 
Thanks.
 

 

[sawickib]

I would carry out the substrate change since yours is a 55 gallon you might get away with just taking the gravel out and leaving the fish in, but it wouldnt hurt to put the fish into a bucket or something and do almost a 100% change along side the gravel change and do a filter cleaning, that way when all the fish are back in the new ammonia will be getting eaten quite rapidly. Now after this fill it back up and everyday do a water reading and make sure everything iss reading zero if it peaks anywhere then i would recommend a 25% water change and keep doing this if you need to until it stables out. I dont think you have to worry to much about spikes and all that though. Whats your full stocking? If its not a bunch and theres not huge waste makers it should be fine. 
 
The geophagus will really appreciate the new sand make sure you rinse it out very well btw pool filter sand isnt as bad as play sand but it still has quite a bit of dust.

 

[Alasse]

I personally would remove the fish in to containers as well as all hardscape (then run the filters in the containers with the fish etc)
 
I would (and have done)
empty the tank of water
remove all the substrate (you will be amazed at the mulm and rubbish you stir up doing this lol)
give the tank a clean
put new substrate in
refill with water
dechlorinate add filter/s and heater etc
bring it up to temp
add fish

 

[tetraodon_biocellatus]

Do I have to worry about dieoff of bacteria in my filters if they are deprived flow for an hour or two? If the fish are on the floor in a holding bin I cant have my gravity fed canister hooked up anyway, but I can hook up the hang off the back. Should I attach the canister to a separate container that I can place on a desk or elevated surface or will a drop in temperature from unheated water damage the colony? 
 
 I am kind of afraid of being judged by the fishkeeping community so keep in mind this is a work in progress.
 
It is heavily stocked though almost all the fish are currently juveniles/subadults and half of the fish are moving to a new 40 gallon (which I am still waiting for a zero ammonia reading on). The tank contains the following:
 
x1 geophagus brasiliensis (4 inch subadult)
x3 Keyhole Cichlids
x2 Kribensis (breeding pair)
x2 Congo Tetras
x3 Bolivian Rams
x1 Siamese Algae Eater 
 
Thanks! 

 

[sawickib]

Your filter should be fine, just keep water in it, you shouldnt have to run it. I would put a bubbler or HOB filter with the fish on the floor.
 
All i would have to add on your stocking is put the kribs and rams in the 40 gallon (i dont know much about your other fish to comment) and up your brasilinesis school to about 5 and congo tetras to 6+ with a good male female ratio.

 

[Alasse]

Do I have to worry about dieoff of bacteria in my filters if they are deprived flow for an hour or two? If the fish are on the floor in a holding bin I cant have my gravity fed canister hooked up anyway, but I can hook up the hang off the back. Should I attach the canister to a separate container that I can place on a desk or elevated surface or will a drop in temperature from unheated water damage the colony? 
 
 I am kind of afraid of being judged by the fishkeeping community so keep in mind this is a work in progress.
 
It is heavily stocked though almost all the fish are currently juveniles/subadults and half of the fish are moving to a new 40 gallon (which I am still waiting for a zero ammonia reading on). The tank contains the following:
 
x1 geophagus brasiliensis (4 inch subadult)
x3 Keyhole Cichlids
x2 Kribensis (breeding pair)
x2 Congo Tetras
x3 Bolivian Rams
x1 Siamese Algae Eater 
 
Thanks! 

It wont take long to empty and fix up the tank, your canister will be fine turned off. I've had mine off for 4 hours or more and had no probs with start up. Just run an air stone & heater in with the fish

 
Can i just add, Kribs are absolutely vicious when breeding. They will kill anything that encroaches on the breeding site, if not kill, beat the living snot out of. You may want to keep an eye on them

 

[tetraodon_biocellatus]

They have had several batches of fry, the other fish hold up well against them. There are plenty of sight barriers and mine only try to control one cave and about a square foot of tank space. The female did however beat the male close to death after their first batch was eaten. But they seem to have made up since then. I even got a fry to live to become a fingerling. It lives alone in a seven gallon and is growing fast. 
 
Thank you for all your help and reassurance, I will definitely up my congo school once I move fish out. Im excited to get this tank in shape.
 
Thanks guys! 

 

[fluttermoth]

One thing I would add; you might well lose some bacteria which will be living in your substrate, so as well as testing daily for the first week or so after the change (and being prepared to do extra water changes, if you do see any ammonia or nitrite), don't feed the fish for a couple of days before and after, or keep it to a bare minimum, so you reduce the amount of waste the fish are producing.

All these things (the testing and the minimal feeding) are precautionary; you really shouldn't have any issues, but it's always best to be on the safe side

Most of us have overhauled tanks, changed substrates, rescaped and other major upheavals with no problems at all, so I'm sure you'll be fine.

We'd love to see some before and after pics, as well (we do love nosing at other people's tanks

)