# swapping out sand?



## huddles (Dec 29, 2009)

anyone ever successfully swap sand (say white for black) in a live freshwater tank without making the bio crap out? too risky to try?

Feedback welcome. tank is 150 gallons. 

huddles


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## Alexpatrascu (Jun 13, 2010)

WOW, 150gal, that looks like a "start from scratch" for me.


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## Ciddian (Mar 15, 2006)

I sorta did it with my 90 but I am telling you its a nightmare :/ Do you have livestock in there now?


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## Riceburner (Mar 14, 2008)

I've done it with gravel in my 4' 60G. I did mine at WC time. Large gravel for finer. Don't see that it would be too different. Make sure the new stuff is ready to go...i.e. cleaned. Scoop out as much of the old as you can and then do the vac and water change....sucking the rest out. Put in the new, replace decor and refill the 50% water you took out.

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## Fergus (Jul 11, 2011)

It's a total complete nightmare if you are using anything like a planting substrate. It's a lesser nightmare if you're using a denser sand or gravel. Bearing in mind though, all of the waste material the substrate has been exposed to will be tossed into the reduced water column during this transition. You'll end up doing a bunch of water changes, and that coupled with the removal of the substrate will destroy any biological filtration happening in the tank. Bacteria colonizing your ornaments and filter media may or may not survive. 

IMHO, you should take the fish out, set them up with filters in buckets. Remove as much of the tank's water as you can store. Grab a high-topped container like a bucket or pitcher, and fill it with tank water and about 3/4 full of old substrate, and set it aside. This will be a seed colony of bacteria for the new substrate. Remove your water, ornaments and old substrate. Add your new washed substrate, and ornaments. put your seed-pitcher in the tank, and put as much of your old water back in as you have. Set up your heater and filtration. Float the fish put the water from their buckets in the tank.

Ideally, you stored enough water that you don't need to immediately top off your tank with new water. In theory, the old gravel in the bucket, your filter media and old tank water should be enough to get your cycle started. Top off the tank at your next water change.

It's like 1000 times worse if you are using a planting substrate.


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## BillD (Jun 5, 2006)

Saving the old dirty water is of little benefit. The nitrifying bacteria aren't in the water column.


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## Fergus (Jul 11, 2011)

The old water is more so that the fish aren't as stressed out by new water chemistry, but yah, you're right. its probably overkill.


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## solarz (Aug 31, 2010)

I think it depends on the bioload and how densely planted the tank is. The lower the bioload, and the more plants you have, the easier the transition will be. Of course, it will be more work to actually take out and replant the plants.

I would take these steps to ensure a smooth transition:

1- Pull out rooted plants and replace them with floating plants. Depending on how many plants you have, you may want to do this over several days.

2- Add extra filter and overfeed to help establish bacteria population on the extra filter and new floating plants.

3- After substrate is changed, do not feed for a few days.

The floating plants will not get stressed out by the substrate change, and will continue to uptake nitrogen. The extra filter will help make up for the loss in biofiltration due to the new substrate. You can replace the old plants after the substrate is changed.


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## Will (Jul 24, 2008)

I did it on a 220 gallon tank. Plant substrate/gravel for silica/aragonite. It was a pain in the ass but was fine. Big cichlids in the tank while going it.


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