Replacing sand bed

[JeffDubya]

When I started keeping reef tanks again after a 10+ year hiatus, I brought some of my old school techniques with me. 4 months later I have a successful tank, thanks mainly to this site and my local fish club. However, if I could change any one thing, it would be the coarse crushed coral substrate I used when I put together this tank.

I read all the time about aquarists switching out their deep sand bed because of accumulation of heavy metals (e.g. copper) and I don't quite understand how they do this without messing with the water quality of the tank. I also don't know if this must be done by removing everything first, replacing the sand, and then replacing everything - or by doing a section at a time, taking out as much as possible and the just covering up the old stuff.

I would LOVE LOVE LOVE to replace my crushed coral with a 2-3 inch sand bed. I currently have about 55 lbs of live rock with fish, inverts, zoos and LPS.

I had considered getting some aragonite, doing a water change... taking the old water and soaking the new sand in that, then taking the old substrate out a little at a time.

I'd love to hear thoughts about this.

[V]

i have crushed coral left over from my previous tank. im currently using it for the FO tank, which although im happy with it, is totally impracticle long term.
smaller grain is better for bacterial reasons, smaller grains = larger surface area!

as a visual example of this principle for those that cant picture it just yet.
if you take a balloon & blow it up, bactera surround the surface. now fill that balloon up with tic tac candy & the the bactera that collonises the tic tac's individual surfaces adds up to more that the exteria of the balloon.

anyways back on topic.. a swap out long term is a viable idea, if it was a coral tank only, you could leave it for a great time longer, your main problem is the waste products of the fish accumaliting in between the larger spaces of the substrate. this will build up a hell of alot quicker than heavy metal toxitity levels. especially the copper note u made reference to. besides killing your animals even in low levels id say the biggest source is using water from the old pipes.if you use RO then thats one less source!

im sure everyone has there own way of this sort of change out. id just say work in stages. maybe grid-square the base with thin acrylic deviders, that way you can take from that area, and fill that area without blending to much and disturbing the bed!
keep the crushed coral for the sump or fuge, if you do this, the benifits havn't left the system at all! just i stress, do it over some period of time, mini cycles will kill ur efforts if u rush it in a weekend!

[Rob]

how you do it will depend on how much is in your tank, if you are packed with LR, it will be quite difficult, but if not, you could move some of the rock to another tank or a sump. to the point where you could stack all the rock and corals to one side, then start working the sand bed swap. start in 1/4-1/3 portions and work your way down.

you could take everything out and into storage containers, replace the substrate and replace everything (including the water) this might might have more impact on your substrate bacteria, however since you are using coarse crushed coral, the potential impact is likely lower

[JeffDubya]

Lots of rock, Rob. It sounds like if I want to do this it is going to involve removing everything from the tank if I want to do this. One more project when I do a closed loop and drill for reef-ready. :) But good to think about.

[Boz]

"your main problem is the waste products of the fish accumaliting in between the larger spaces of the substrate. this will build up a hell of alot quicker than heavy metal toxitity levels. especially the copper note u made reference to. "

This happened to me, and like you, I had just come back to the hobby after a hiatus. I learned the hard way that - crushed coral traps a lot of debris..... my LFS helped me out with a rush purchase of some live sand from their in store back room stock and I did the swap out overnight. Live rock to the tub with wet towels on it, lots of scooping and a quick 20% water change. Fortunately it was only a 55 gallon!

[CarmieJo]

Hi Boz

I don't think that I have said :welcome: to TR.

[Boz]

Thanks CarmieJo! Its so nice here. I just got back from a wedding and am checking out the tank under the moonlights - makes you want to stay up ALL NIGHT and watch!

[Amphibious]

Thanks CarmieJo! Its so nice here. I just got back from a wedding and am checking out the tank under the moonlights - makes you want to stay up ALL NIGHT and watch!I know what you mean, Boz. My Solaris LED lights are on the cycle of the sun/moon and moonlights come on right at sunset. I'm a night owl and really liked having my MHs on late into the evening but since I've had my Solaris I've gotten to like the "moonlight". The fish are out cruising slowly. I'm amazed at how many corals fluoresce under the moonlights. That is really cool. It reminds me of being out on a date and having the moonlight bounce off my dates glitter makeup. :rotfl:

[CarmieJo]

I love night viewing. Too bad I usually have to get up & go to work the next morning!

[V]

HAHA, glitter makeup. those were the days Ampage:agree:

[Amphibious]

Yeah, that popped into my head as I was thinking of a funny analogy of the moon light shinning on something.