Thinking of Swapping the sand in my reef tank

[tcampbell23]

Hey all,

I have been contemplating swapping out the sand in my reef tank for a while now and as of late, I am a little more apt to do it. I currently have black sand in my tank and it was really cool at first but, it makes the tank seem really dark and drab. The corals do pop off of the black but the tank overall is sort of dark and gloomy. Depending on the feedback I get, I will look into putting white sand or crushed coral in.

My concerns:
1. Nutrients. The tank has been up for about 8 months. I have never really siphoned the sand consistently so I am sure there is detritus and other uglies trapped in the sand bed. How can I go about removing the sand without causing a major spike in NO2,NO3, and PO4.

2. I set this tank up in a hurry as I was moving and the timing didn't allow for careful planning. In doing so, I set my rocks up on the sand bed instead of the bottom glass. I would like to go back and put eggcrate under the rock structures to aid stability.

Many of my rock structures do not have a lot of sand under them and if I can remember properly, I tried to push the rocks through the sand to the glass as much as possible but, I can't be certain.

My plan of action:

Over the course of weeks (6-8 weeks) I will siphon out sand in sections as I do my water changes until there is not much left. Then, over the next 6-8 weeks I will add new sand to the tank. As i go, I will attempt to lift the rocks just enough to wiggle some egg crate under each structure to add stability.

I am not 100% sold on doing this as the black sand isn't ruining the tank for me but, it's a novelty that I have lost interest in and would love to go back to the bright and beautiful white sand. I want to hear opinions on this as I could go either way.

Thanks guys and gals.

 

[tcampbell23]

I guess I should add that I didn't glue most of my rock structures together either.

 

[Jason mack]

Sounds like a good plan...!!! How big is your tank ,, how big are your rocks , I would certainly get someone too help you when putting your egg crates under .. one person lifting and one sliding egg crate .. last thing you want is too drop a rock or have one fall on your glass bottom .. I hope it works .. good luck !

 

[tcampbell23]

Sounds like a good plan...!!! How big is your tank ,, how big are your rocks , I would certainly get someone too help you when putting your egg crates under .. one person lifting and one sliding egg crate .. last thing you want is too drop a rock or have one fall on your glass bottom .. I hope it works .. good luck !

It's a 5 foot 120gal. Most of my rocks are under 10 pounds with the exception of one that's about 15-20 pounds.

 

[nervousmonkey]

Sounds like a good plan, I really like white sand. Some things to think about:
1. How deep is the current sandbed? If more than 2" you may release more than just nitrogen and phosphates. But a good suction will help a lot here along with a 25% WC after each siphoning.
2. Keep in mind that the eggcrate traps a lot of stuff, so that creates even more of a nutrient/detritus sink. It's probably too late, but acrylic rods glued to a square acrylic plate solve this problem. Easier said than done in your case though, but in the long run much better, and you don't want to say in 2 years that you were in a hurry to get the eggcrate underneath and didn't plan better. Good thing your rocks aren't glued together, it's OK they aren't, esp if they aren't being tipped over. This may be a good time to take each rock out and put into a cooler for the time being while you execute a well planned change in your tank.
3. Some good sand stirrers/a new CUC will help keep the sand clean: nassarius snails are my favorite as the live under the sand and move around like little submarines. Conch's are good at keeping the sand clean and if you don't have a lot of corals sitting directly on the sand, great plan here. You could have two, but one would work. If you have a lot of corals on the sand, never mind the conchs..
4. Great idea to do it in sections; think about how long between each section you want to take. It would help to wait two hours after each siphoning of the sand out of the tank and measure your nutrients to see the change in levels. If there isn't much of a change you can accelerate your plan, and vice versa obviously.
5. How deep do you want the new bed to be? The shallower the less build up you will get and the easier to maintain.
6. Since you are taking time in between adding the new sand, it's a great time to see how a barebottom tank feels and looks, and also to get nutrient levels under control. Point powerheads at the bottom to get detritus off the bottom and into the water column to be sucked into the overflow and into the sump for removal.
7. Since you are taking time to do it right, I would think about the acrylic idea. See Synergy Reef build, page 6 post 118 for reference, linked here: It would not be that difficult over the course of 6-8 weeks to do something like this. I did that to one of my tanks and it is spectacular. Keeps rocks off the glass but super stable and not easily knocked over. In two years I've never had a rock move in that tank.

Either way, good luck! It'll be a fun endeavor and chance to change your tank completely to something that you like and have no worries about.

Cheers,

Lloyd

 

[tcampbell23]

Sounds like a good plan, I really like white sand. Some things to think about:
1. How deep is the current sandbed? If more than 2" you may release more than just nitrogen and phosphates. But a good suction will help a lot here along with a 25% WC after each siphoning.
2. Keep in mind that the eggcrate traps a lot of stuff, so that creates even more of a nutrient/detritus sink. It's probably too late, but acrylic rods glued to a square acrylic plate solve this problem. Easier said than done in your case though, but in the long run much better, and you don't want to say in 2 years that you were in a hurry to get the eggcrate underneath and didn't plan better. Good thing your rocks aren't glued together, it's OK they aren't, esp if they aren't being tipped over. This may be a good time to take each rock out and put into a cooler for the time being while you execute a well planned change in your tank.
3. Some good sand stirrers/a new CUC will help keep the sand clean: nassarius snails are my favorite as the live under the sand and move around like little submarines. Conch's are good at keeping the sand clean and if you don't have a lot of corals sitting directly on the sand, great plan here. You could have two, but one would work. If you have a lot of corals on the sand, never mind the conchs..
4. Great idea to do it in sections; think about how long between each section you want to take. It would help to wait two hours after each siphoning of the sand out of the tank and measure your nutrients to see the change in levels. If there isn't much of a change you can accelerate your plan, and vice versa obviously.
5. How deep do you want the new bed to be? The shallower the less build up you will get and the easier to maintain.
6. Since you are taking time in between adding the new sand, it's a great time to see how a barebottom tank feels and looks, and also to get nutrient levels under control. Point powerheads at the bottom to get detritus off the bottom and into the water column to be sucked into the overflow and into the sump for removal.
7. Since you are taking time to do it right, I would think about the acrylic idea. See Synergy Reef build, page 6 post 118 for reference, linked here: It would not be that difficult over the course of 6-8 weeks to do something like this. I did that to one of my tanks and it is spectacular. Keeps rocks off the glass but super stable and not easily knocked over. In two years I've never had a rock move in that tank.

Either way, good luck! It'll be a fun endeavor and chance to change your tank completely to something that you like and have no worries about.

Cheers,

Lloyd

Thanks for the detailed response!

1. My sandbed ranges from 1/4" or less to 2" in some places. What if when I get to a deeper section, I do it one layer at a time with a week or so in between to allow my tank to handle whatever is released and have saltwater pre-mixed to do a 20% water change if need be?

2.My rocks are currently covered in corals and I like my aqua scape as it is so I don't have much desire to take everything out and redo it although it is an option.

3.I definitely need to invest in a clean up crew as my tank pretty much lacks one altogether (hermit crabs killed the snails and then in turn suddenly died).

4. Great advice. If I could do this faster than 2 months then I would be happy to but I am not in any hurry as my corals are growing well and I dont wantto go through a browning out and dying off phase.

5. I do not want the sand bed very deep at all. I'm thinking about 1-1.5" at most (more likely to be an inch or less). I want something easy to maintain with larger grain sizes that wont be blown around when I crank up the flow.

6. Another excellent point. I don't think bare bottom is for me. I love the natural look of sand and the various reef inhabitants that interact with it. However, I will definitely take advantage of the bare bottom phase to get nutrients under control.

7. I actually follow that build and its an excellent idea. I don't think its something I will do but, I am open to the idea of it as it's not completely impractical.

Thanks a ton for your advice. I really appreciate it!

 

[tcampbell23]

Picture of my tank for reference

 

[nervousmonkey]

Thanks for the detailed response!

1. My sandbed ranges from 1/4" or less to 2" in some places. What if when I get to a deeper section, I do it one layer at a time with a week or so in between to allow my tank to handle whatever is released and have saltwater pre-mixed to do a 20% water change if need be? I think you're fine, as long as there wasn't a deep enough sand bed, say 2" or greater all over the tank, then you don't have a DSB that would build up the dangerous sulfides. I would still definitely have saltwater mixed up for a change after siphoning the sand out though; the size of the WC being dependent on how much escaped into the surrounding water as opposed to being able to get all of the water and sand out with the siphon. Testing your water a couple hours, or less really, after removing the sand will also tell you how much to do. If you remove some every week and do a 20% WC you'll be fine. I just don't like changing a lot of water all at once.

2.My rocks are currently covered in corals and I like my aqua scape as it is so I don't have much desire to take everything out and redo it although it is an option. I don't think you need to redo the aquascape at all, now that I have a picture of it, it makes a lot more sense. Frankly I think it will be difficult to pull up the rocks enough, esp. some of those ones in the middle, to put eggcrate under the bottom rocks without risk of toppling the top rocks. All I am saying is to take the top rocks out and put into a cooler for the 10 minutes it takes to make the changes you want to make. Once you have put a few of the pieces of rock structure on top of eggcrate, when there is no sand and it's effectively a BB tank, I think you'll understand what I mean about the eggcrate trapping a lot of nasty stuff that a CUC that cleans the sand couldn't even help you with. Detritus isn't all bad though; maybe you could think about making that area an anoxic zone, so de-nitrifying bacteria populated it and consumed the detritus from the eggcrate, and at the same time, converted nitrates back to N2 gas. That is most easily achieved underneath sand, where oxygen cannot get to. Think about getting some media you could put inside the eggcrate holes, like Matrix, broken up Marine-Pure or something similar. Then you eliminate the issue of detritus buildup and after a few months, have a natural way to export nitrates.

3.I definitely need to invest in a clean up crew as my tank pretty much lacks one altogether (hermit crabs killed the snails and then in turn suddenly died). Get Nassarius snails first. I hate hermits; they are mass murderers and don't even hide the evidence. Complete lack of remorse for their crimes against snail-manity. LOL

4. Great advice. If I could do this faster than 2 months then I would be happy to but I am not in any hurry as my corals are growing well and I dont wantto go through a browning out and dying off phase. Agreed, please take your time doing this, it'll keep everything more stable.

5. I do not want the sand bed very deep at all. I'm thinking about 1-1.5" at most (more likely to be an inch or less). I want something easy to maintain with larger grain sizes that wont be blown around when I crank up the flow. Good choice.

6. Another excellent point. I don't think bare bottom is for me. I love the natural look of sand and the various reef inhabitants that interact with it. However, I will definitely take advantage of the bare bottom phase to get nutrients under control. yeah, I don't like BB either, I like natural.

7. I actually follow that build and its an excellent idea. I don't think its something I will do but, I am open to the idea of it as it's not completely impractical. This could be accomplished pretty easily and if you didn't create acrylic rods that were that tall, maybe 1-1.5", it would work really well, just lifting the rocks a little more than for eggcrate.

Thanks a ton for your advice. I really appreciate it!

Anytime! And rinse your new sand for at least an hour to get the silicates out. I prefer dry sand to live sand, but it's getting harder to find it. Anyway, rinse well and you won't have to worry about diatom blooms, or get PhosGuard or a product like it that removes phosphates as these products almost all remove silicates as well. I say Phosguard because it's so quick and short acting and removes silicates from the water quickly. At least it would keep diatom blooms away.

 

[orbitee2015]

I have a Red Sea 350 90 Gallon. Had black sand and switched to white. Switched it out over time but still having diatom issues. I'm still not sure if I regret it yet or not. I didn't rinse the new sand as someone said which may have been my issue I used carib sea non live sand about 2" deep. I'm running Rowaphos and using my RO buddy water but just can't get rid of them. So All I'm saying is clean white is nicer but no diatom black is better.