Moving my sandbed

[jimeluiz]

Our move to Brazil approaches. We should be on a plane to Florida to spend time with my mother before Xmas, then on to Rio in January.

I have attracted a buyer for our entire setup (!) - but I must say the prospect of moving this thing is daunting and keeps me from setting a date certain.

One question I have is about moving the sandbed. We have a 5 inch deep sandbed that has been living (and absorbing gunk) for about five years. It is filled with critters that I would like to try and transfer to the new location/setup. But I also think we should probably toss a good amount of the sand, as it is surely nasty. Bring in some new stuff to mix in.

So what do you think? Can I just sift through the sand and try to capture some of the larger critters, then maybe transfer a bucket or so of the old stuff and mix it all into some new live sand from the lfs? How much of the old sandbed would you transfer to the new location?

Thanks for your thoughts/experience on this one.

 

[Woodstock]

I would set up your new tank with new sand. Old sand is not necessarily a good thing. Seeding your new sandbed with a few cups of the top section of your old sand would work fine but keep in mind that moving large amounts of live sand is difficult. The bacteria/fauna require HUGE amounts of oxygen (the anaerobic bacteria require oxygen free area) and once you start stirring/mixing the sand, you not only kill the anaerobic bacteria but you could also suffocate the aerobic bacteria & bugs. Keeping large amounts of sand alive in containers will be difficult.

IMO, periodic replacement of small sections of an old sand bed is an important part of maintenance.

 

[flricordia]

Once the LR is all removed you can remove the first couple of inches carefully with a net, slowly so as not to cause too much stirring, and this should get most of the critters. This layer, besides being a little dirty, should be fine for immediate reuse. You can mix some new water give the sand a bath to get most of the excess gunk out and be able to save most all inhabitants, bacteria included. Then by leaving a few inches of water in the tank above the remaining sand you can stir it up over and over to release any hydrogen sulfide gasses, then place it into some fresh salt water and stir it again, and it should be fine to reuse.

 

[zimboy]

Be certain to have all livestock out of the tank before disturbing your sandbed if you want to sift through it. Your sandbed will surely leach much accumulated nastiness into the water column once you stir it up, and this will very quickly kill all inhabitants. I cannot remember the toxic gas that is produced in sandbeds (some type of sulphide?) but disturbing the sand past the top 1-2 inches will probably release this. If you want to transfer some of the sand over, carefully scoop a little of the top layers and add it on top of new sand in the new setup. Your prospective buyer will have to wait for the sandbed to mature and start supporting anaerobic bacteria. I do not think you could transfer the sand without killing most of the anaerobic bacteria and a good portion of the aerobic bacteria and fauna, just as woodstock says above

 

[flricordia]

Be certain to have all livestock out of the tank before disturbing your sandbed if you want to sift through it. Your sandbed will surely leach much accumulated nastiness into the water column once you stir it up, and this will very quickly kill all inhabitants. I cannot remember the toxic gas that is produced in sandbeds (some type of sulphide?) but disturbing the sand past the top 1-2 inches will probably release this. If you want to transfer some of the sand over, carefully scoop a little of the top layers and add it on top of new sand in the new setup. Your prospective buyer will have to wait for the sandbed to mature and start supporting anaerobic bacteria. I do not think you could transfer the sand without killing most of the anaerobic bacteria and a good portion of the aerobic bacteria and fauna, just as woodstock says above

Sure you can. As I explained in the above post all the sand can be saved. Of course all the tank inhabitants need to be removed. I think anyone would know that. And then removing the first couple of inches with a net very carefully, then stirring the remaining and rinsing in fresh salt water, replacing it as the bottom layer and the first removed as the top again will work fine and there shouldn't be any bacteria or sand-dwelling creature loss.

 

[zimboy]

Sure you can. As I explained in the above post all the sand can be saved. Of course all the tank inhabitants need to be removed. I think anyone would know that. And then removing the first couple of inches with a net very carefully, then stirring the remaining and rinsing in fresh salt water, replacing it as the bottom layer and the first removed as the top again will work fine and there shouldn't be any bacteria or sand-dwelling creature loss.

How will your anaerobic bacteria survive being exposed to oxygen rich water? In my understanding oxygen will kill the anaerobic bacteria? by stirring the bottom of the sand with NSW you will surely be introducing oxygen into an oxygen depleted zone. I'm sorry if i have this wrong, but if anaerobic bacteria could survive being exposed to oxygen then they would not BE anaerobic and it wouldn't take so long for them to mature. It takes a dsb about a year to mature because this is the time it takes for all the oxygen in the bottom of your bed to deplete and for the anaerobic bacteria to colonise. Again i apologise for going on and on, but please correct me if i'm wrong...

 

[jimeluiz]

So glad I asked.

Our rock is in very large pieces and three pieces are sitting on the bottom of the tank, so removing them will create quite a stirr (pun intended!)

I think I'll scoop out some sand from the top layer, then pull out the final rock pieces and get them into some clean water.

I'm interested to see how the discussion above resolves itself - it would be great not to have to buy all new sand -- but the health of the tank is #1.

 

[zimboy]

I think that flricordia's method will work the best as it will allow you to reuse your sand, but i am pretty certain that you will lose your anaerobic denitrifying bacteria. probably not the aerobic bacteria or other meio and microfauna, which is maybe where flricordia's and my disagreement stems from, possibly just miscommunication....

 

[flricordia]

Yes, the anaerobic will mostly be lost, but will recover fairly quickly. There will not be a drastic recycle as long as the aerobic is kept in good condition. Plus, the LR contains anaerobic in itself. I have moved DSB like this before and had no ill effects. The main concern is to remove the hydrogen sulfide (the rotten egg smell). It disipates fairly quickly. It will suface as gas and leave the water into the air. Just keep a couple inches of water above the sand so it will disipate quickly. Just stir the bottom sand once you get out what you want to survive and smell each scoop of the net. If it smells OK then it is OK to use. If it smells rotten, then you will need to reclean it in fresh salt mix.
Treat the top layer like you would your LR and you should be treating your LR like a coral IMO.
You are going to be throwing away perfect good sand if you decide to just toss it and start fresh, plus you will loose much benificial bacterias.

 

[Woodstock]

If you've never had algae issues and the sand is young, you could reuse it. If the sand is over 1 yr or if you have had algae problems, I would only use a small portion just to seed a new sand bed.

Remember that phosphates can precipitate onto the surface of calcium carbonate (aragonite sand) and later leech out into the water.

Chemistry and the Aquarium

Likewise, phosphate can precipitate onto the surface of calcium carbonate, such as onto live rock and sand. The absorption of phosphate from seawater onto aragonite is pH dependent, with the maximum binding taking place around pH 8.4 and with less binding at lower and higher pH values. If the calcium carbonate crystal is static (not growing), then this process is reversible, and the aragonite can act as a reservoir for phosphate. This reservoir can make it difficult to completely remove excess phosphate from a tank that has experienced very high phosphate levels, and may permit algae to continue to thrive despite cutting off all external phosphate sources. In such cases, removal of the substrate may even be required.

 

[jimeluiz]

Remember that phosphates can precipitate onto the surface of calcium carbonate (aragonite sand) and later leech out into the water.

This is a very helpful reminder. I have been playing chicken with the tipping point vis a vis the precipitated phosphates and the resulting cyano nuisance.

I think I'll skim off some sand and get the new setup off to a fresh start.

Thanks all.