switching substrates on up and running tank

[robandrosco]

Well title said it all. I want to switch from crushed coral to sand. Is there an easy way to do this with little stress to my fish?
Im pretty sure the crushed coral is giving me my nitrate issues.

Thanks in advance.

75gallon
nitrate 40ppm

[dlhirst]

If you think the nitrates are coming from the substrate then anything you do to remove it will likely be less stressful on the fish than 40ppm of NO3. If at all possible, you should try to find some "live" sand - something that has been in an existing system for some time. But, my thought is that even dry sand would be preferred to the crushed coral IF that is where you are getting nitrates.

[robandrosco]

I agree with everything you said above. Just wondering what process i should go with to change it out.. little by little scoop out the crushed coral or take all the rock and fish out completely remove the CC and put my new sand in.
Taking everything out would be a PITA but if it must be done, it must be done.

Any idea how much sand I will need to buy for a 75g tank?

[MyNemesis]

I have done this twice - a 55 gallon and a 180 gallon. Both were switched over to sand in one weekend., with no spikes or lost animals. Many problems in tanks are undoubtedly due to the crushed coral. When you vacuum out your CC substrate, you are not getting at the junk accumulated underneath your reef structure. I had crushed coral for years and went through Nitrate and algae difficulties. Nitrates would go down after a water change and then go right back up. You will be so happy with a sand bed, I promise. You shouldn't need to "seed" your new sand if you have established live rock, as a great deal of the bacteria needed is contained in your rock, but I always do anyway. Start on a Friday night. Take out tank water before it gets all mucked up to fill whatever you will store your animals and live rock in until Sunday evening. Remove your animals and put them in your rubbermaid or whatever with powerhead and heater for a day or two till the sand settles, and then remove your live rock, which starts to yuck things up. Then start the gross part. Drain the water down as far as you can. Discard the water. When you see how gross it is you will not want to reuse it. Take out ALL crushed coral and all the smelly gunk and throw it away. Use this opportunity to clean your tank thoroughly before it is set back up. Use Vinegar if needed for tough cleaning jobs and rinse thoroughly. Good opportunity to clean everything else as well, powerheads, returns and so on. I would rinse the new sand three or four times to get rid of the fine dust. It will settle quicker that way. After the tank is cleaned you start to put it back together. Add the rinsed sand (some put egg crate under the sand bed to prevent any damage to the glass) to the tank. Then you have to add salt water. Some reefers maintain that you should use old water from the prior set up to speed up the process. There is very little in the water that is beneficial to the new set up. I would only do this if you can't afford all new water. I prefer to add a handful of "live sand" to the sand bed to seed it, as opposed to trying to use old water. You can get this from a LFS or a fellow reefer you trust. Adding the water is important. Go as slowly as you can, put something on the sand bed to pour or drip the water into to prevent as much disruption of the sand as possible like a shallow bowl, or a piece of plastic. It doesn't matter if it takes several hours to fill - this will affect how quickly you are able to see into the tank to put stuff back together. After the tank is full, add powerheads, filtration, heater to bring it up to temp and wait until you can see into the tank. This will take a day. If you have everything set back up by Saturday afternoon, you should be able to see into the tank to put the rock and critters back in by Sunday afternoon or evening. Put your live rock back in the tank, make sure your temp is good. If you want to acclimate anything delicate with fish and corals, that is fine too. Then put it back together. Should be a good weekend project. Keep us posted!

[robandrosco]

Wow thank you for the write up! Sounds like a perfect plan. From my research 80 pounds will do a 3 inch sand bed in my tank so I will probably do that. 2 30 pound bags of dry and 1 20lb bag of live.

Bahama oolite or fiji pink?

[Tom@HaslettMI]

That's a good plan and write up John.

Currently I'm contemplating removing my 15 year old sand bed and either going bare bottom or replacing the sand. My plan is a little different. I'm going to suck as much out as I can during water changes. It will take awhile but it will allow me to (hopefully) keep my rockscape as is. Either way should work, and there are probably other methods too.

Tom

[robandrosco]

geez 20 years old eh? Who knows whats under there.

[Tom@HaslettMI]

Oh wait. Correction: 15 years. I ran 5-ish years bare bottom. I will edit the earlier post.

Tom

[robandrosco]

Well went out to fish doctors today and picked up my sand. went with caribsea ocean direct Caribbean (40#) and a 30# bag of aragamax sugar sand. mixed in a bit of my old crushed coral for some diversity and bam done!

picked up a blue hippo tang and some snails too.

heres some pics of the temporary holding tanks

Another couple hours and some aquascaping and I will be able to add the fish and corals back.