Redoing rockwork...Replace Sand?

[IndyReef78]

Here’s the scoop and I could use some opinions specific to the situation:

120 gallon mixed reef tank up and running in some form for about 20 months. I aquascaped with Marco rock and Quickcrete Hydraulic cement about 3-4 months ago and in the last week or so, most of the structures have begun to or completely crumbled. So I will have to redo the rocks.

We have a maybe 3 inch fine sand bed (made up of Caribsea live sand) that is quite dirty. We battled nitrates for a long time and had finally gotten that battle won with the help of NoPox, but since the rocks shifted, the sand has been disturbed.

The questions are these:

1.) Should we drain the tank and start over with new sand since we’re redoing the aquascape anyhow?

2.). If we do new sand, would you use live or dry and fine or coarse texture and why?

3.) Should we drain the tank and then thoroughly rinse the old sand and reuse with a big water change?

4.). Should we leave the sand alone and hope for the best once things settle back down rather than stirring up a potential major mess? Our water parameters had been reading just fine prior to all this.

I have been trying to research, but honestly, we need to do something sooner rather than later, so any advice would be much appreciated.

 

[Softhammer]

I’d do option 3.

 

[Saltyreef]

Perfect excuse to go bare bottom with starboard!
If you are set on keeping the sand, remove all of it and rinse with jet spray in a tote or buckets until the water runs clear. Then do a final rinse with RODI before putting back in the tank. After that you can replace 100% of your water, dump in a couple bottles of live bacteria and if you really want to jump start life, add a bag of pods.

 

[Saltyreef]

@brandon429 Also this guy has some amazing threads on sand rinsing. Lots of success stories.

 

[IndyReef78]

Perfect excuse to go bare bottom with starboard!
If you are set on keeping the sand, remove all of it and rinse with jet spray in a tote or buckets until the water runs clear. Then do a final rinse with RODI before putting back in the tank. After that you can replace 100% of your water, dump in a couple bottles of live bacteria and if you really want to jump start life, add a bag of pods.

Thanks for the reply. I know we prefer to keep the sand just because we prefer the look, but AI would like to lose a little of the depth and a LOT of the dirt! Do you mind if I ask why it’s preferable to rinse the old sand to just replacing with new? From what I understand, the rocks provide enough beneficial bacteria for the tank, so the amount lost in the sand wouldn’t be crucial ( we also run a refugium/sump). I’m just curious.

 

[IndyReef78]

@brandon429 Also this guy has some amazing threads on sand rinsing. Lots of success stories.

I think I started reading through some of his stuff, but just got overwhelmed!

 

[Saltyreef]

Thanks for the reply. I know we prefer to keep the sand just because we prefer the look, but AI would like to lose a little of the depth and a LOT of the dirt! Do you mind if I ask why it’s preferable to rinse the old sand to just replacing with new? From what I understand, the rocks provide enough beneficial bacteria for the tank, so the amount lost in the sand wouldn’t be crucial ( we also run a refugium/sump). I’m just curious.

Its your choice, even if it was new sand, i'd make sure its rinsed well even then.
Most of the "live" sand in a bag is the worst to just dump in a tank and let the cloud naturally settle. Lots of stuff for the neussiance algae and unwanted bacteria to feed off of for a long time hindering the beneficial bacteria from taking a firm hold in colonization.

 

[Softhammer]

I have done several long range moves and tank re sets, all with full sand beds and if you are going to keep sand it’s always preferable to keep what you have if you are happy with the composition of the sand (size/general appearance). 1 rinse/ flush it. Agitate it with SALT (old tankwater) water, it won’t be totally clean but still live. Do not use garden hose unless you want to kill everything in it which will create a bigger problem than you started with unless you clean it 100% and then prepare to re “cycle” it as if it were new. Also to redo with new sand, you may not be recycling the tank per se but you will be recycling the sand. Expect cyano and diatoms. They will re occur. If you don’t believe me, take a cup of sand, wash it as stated in an above post and smell it a day later. It will make you throw up, the amount of decomposing life in sand is insane.

 

[Bruce60]

Thanks for the reply. I know we prefer to keep the sand just because we prefer the look, but AI would like to lose a little of the depth and a LOT of the dirt! Do you mind if I ask why it’s preferable to rinse the old sand to just replacing with new? From what I understand, the rocks provide enough beneficial bacteria for the tank, so the amount lost in the sand wouldn’t be crucial ( we also run a refugium/sump). I’m just curious.

I would say the answer to that question is the value of money versus time.

New "live" sand costs quite a bit of money, yet you do not have to rinse, unless you want to get some of the silt out of the sand. Rinsing out old sand costs virtually nothing in money, yet takes quite a bit of time and energy.