Thinking about Switching to Bare Bottom

Patrick Cox

Active member
I have a 100G primarily SPS tank that I have been running since February, 2016 and I have battled algae a few times over that period, as most do I would guess. It's not terrible but I am trying to keep it from getting there. So I am thinking about gradually switching to bare bottom. The way I would get there is to vacuum up the sand bed during water changes until it is all gone. (I have a new larger gravel vacuum that takes up a lot of sand anyway.) So any thoughts on this? Will bare bottom help towards keeping nutrients under better control? I am thinking I can vacuum up detritus more easily that way. Also fyi, I have always vacuumed my sand bed so there should not be any danger here.

Thanks!
 
I did the same thing as you're thinking over a year ago (I honestly can't remember now). I'm curious how long has the sand bed been in service? Do you vacuum it regularly and have good flow over all areas of it?

Personally, I had to take other measures along with it to get nutrients down but it definitely helps to keep detritus suspended which is always a plus.
 
Personally I dont like running a reef BB. I tried it twice on 2 systems and had some issues. Mainly alk was harder to keep stable, still do able but needed to be watched closey. Also it did not seem to help with algae much if any, for me at least. Finding a happy compromise with flow was challenging. There are pros and cans to having or not having a sand bed.
 
I did the same thing as you're thinking over a year ago (I honestly can't remember now). I'm curious how long has the sand bed been in service? Do you vacuum it regularly and have good flow over all areas of it?

Personally, I had to take other measures along with it to get nutrients down but it definitely helps to keep detritus suspended which is always a plus.

I have had the sandbed since I started the tank. So since Feb, 2016. I do vacuum it when I do water changes. Mostly in the areas where the fish do their business. :fish1: I have two MP40s in a 4 ft tank. I have thought about adding a powerhead to the back of the rock work as well.

I think my main issue is that I have to feed a lot and I am certain that food ends up in the sand bed and I am thinking that BB would allow me to clean that up a bit better.

Thanks.
 
Personally I dont like running a reef BB. I tried it twice on 2 systems and had some issues. Mainly alk was harder to keep stable, still do able but needed to be watched closey. Also it did not seem to help with algae much if any, for me at least. Finding a happy compromise with flow was challenging. There are pros and cans to having or not having a sand bed.

Thanks for the comments. I didn't realize that BB would not maintain Alk as easily. Were you dosing? I dose 2-part on dosing pumps.
 
What are your actual nutrient levels.

Were are the nutrients coming from? Usually, sand helps to process the nutrients along with other maintenance and a fuge (or other Phosphate export).

If the nutrients are coming from dry/dead rock, then this will not help.

You need to stop vacuuming your sand bed and let it settle into oxic and anoxic areas. Once this is done, it should take your N down under 1 and very healthy. This could be why you have nutrient issues... it does better if not disturbed for long periods of time. (I do vacuum mine starting in year five and only doing about 20-25% every quarter - I do this slowly so that the anoxic zones can re-establish)
 
What are your actual nutrient levels.

Were are the nutrients coming from? Usually, sand helps to process the nutrients along with other maintenance and a fuge (or other Phosphate export).

If the nutrients are coming from dry/dead rock, then this will not help.

You need to stop vacuuming your sand bed and let it settle into oxic and anoxic areas. Once this is done, it should take your N down under 1 and very healthy. This could be why you have nutrient issues... it does better if not disturbed for long periods of time. (I do vacuum mine starting in year five and only doing about 20-25% every quarter - I do this slowly so that the anoxic zones can re-establish)

I will need to measure my nutrients but I have found that these measurements are misleading because the nutrients are being consumed by algae anyway. In the past I have measured 0 nitrate and 0 phosphate with algae growing in the tank and I don't think that is actually possible. Meaning the algae is consuming the nutrients, thus the zero reading.

I don't think my live is rock is the problem because early on I did have this problem with my live rock but that eventually ended. Going on 2 years now. I think the nutrients are coming from food debris in the tank. There always seems to be food crumbs that end up floating to the bottom. I feed 1/2 cube spirulina per day with some nori sheets added in for a 5" fox face , 3" Kole tang, clownfish pair, yellow assessor and possum wrasse. If I feed less than this the fox face starts losing weight.

I wasn't aware about not vacuuming the sand. There seems to be so much fish poo in certain areas that I feel like I have to vacuum that up. I was thinking that vacuuming the sand was a way of removing waste that will break down and create more nutrients. I will have to think about this.

Thanks for your comments.
 
I was always skeptical and anti-BB for the better part of the past decade, decided to give it a fair chance last summer and never looked back. It has its pros and cons, i've never had any stability issues.
 
I was always skeptical and anti-BB for the better part of the past decade, decided to give it a fair chance last summer and never looked back. It has its pros and cons, i've never had any stability issues.

I've been running bare bottom for 4 years and have never had an issue with alk stability. I'm not sure who dreamed that up but like many things in the hobby its BS.
 
Siphon it you will be fine. I have always had no issues removing it all in one go. Done it twice. Make sure your rock is stable.
 
Siphon it you will be fine. I have always had no issues removing it all in one go. Done it twice. Make sure your rock is stable.

Thanks! And good advice on the rock! I put my rock in before my sand so I should be ok but will pay attention to that.

Sounds like a good holiday project!
 
Iā€™ve been running bare bottom for 4 years and have never had an issue with alk stability. Iā€™m not sure who dreamed that up but like many things in the hobby its BS.

Not made up BS. Real world experience. Once my sand bed was removed my alk went from stable at 8 and would drop unless I kept up on dosing daily. This very well may not be the case for everyone running BB but it was for me. Once I added a sand bed back in alk stayed a lot more stable. If you already have a 2 part doser or use kalk then alk shoukd not be a problem. I was dosing manually every few days as needed for ca and alk using Brightwells 2 part and needed to test and dose alk daily or it would drop below 7. Please dont make false claims just because your tank did not experience low alk, every tank is different. What works for one person or tank may not work for another.
Now if you already have a high demand for alk and already have a dosing system that keeps the tank stable then you may not notice/have alk issues.
 
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Don't assume that going bare bottom means no more siphoning of the bottom of the tank. If you have dead spots with flow now they will still be there. A monster clean up crew could help out as well. Mix up snails that like to bury in the sand with ones that don't along with a nice group of crabs.
 
Not made up BS. Real world experience. Once my sand bed was removed my alk went from stable at 8 and would drop unless I kept up on dosing daily....

I don't really follow this. I dose daily now with a sand bed. Are you saying that I may need to dose more without a sand bed?
 
Don't assume that going bare bottom means no more siphoning of the bottom of the tank. If you have dead spots with flow now they will still be there. A monster clean up crew could help out as well. Mix up snails that like to bury in the sand with ones that don't along with a nice group of crabs.

Thanks and yes, I understand. At least the waste will be easier to find! šŸ˜
 
Large cuc is a bad idea. If it's just to remove the pest algae then removing them or most from the tank thats fine. You dont want all those snails and crabs to die after all the algae is gone. Here is what will happen. Add cuc, cuc eats most of the algae and you remove the rest with cleaning, nutrients issues is resolved leaving little algae growth, cuc dies releasing all the nutrients they consumed by eating the aglae back into the system, now you are right back where you started. Removing the cuc after the issue is resolved not only prevents their death but removes the nutrients from the system. Keep only what your system can sustain, for 100g reef I would have under 20 snails and maybe 5-10 hermits total, 1-2 emerald crabs and a few tangs. The 1-2 snails per gallon rule is way to many.
 
Large cuc is a bad idea. If it's just to remove the pest algae then removing them or most from the tank thats fine. You dont want all those snails and crabs to die after all the algae is gone. Here is what will happen. Add cuc, cuc eats most of the algae and you remove the rest with cleaning, nutrients issues is resolved leaving little algae growth, cuc dies releasing all the nutrients they consumed by eating the aglae back into the system, now you are right back where you started. Removing the cuc after the issue is resolved not only prevents their death but removes the nutrients from the system. Keep only what your system can sustain, for 100g reef I would have under 20 snails and maybe 5-10 hermits total, 1-2 emerald crabs and a few tangs. The 1-2 snails per gallon rule is way to many.

Thanks. I don't have any hermits. I found in the past that they just kill the snails. I do have a few small crabs that came with my Live Rock and then I have probably 10 snails left. (A few have died.) I don't plan to add a bunch more snails. I am going to start removing sand though to see if that helps. I can always add sand back if I don't like it. Thanks.
 
Not made up BS. Real world experience. Once my sand bed was removed my alk went from stable at 8 and would drop unless I kept up on dosing daily. This very well may not be the case for everyone running BB but it was for me. Once I added a sand bed back in alk stayed a lot more stable. If you already have a 2 part doser or use kalk then alk shoukd not be a problem. I was dosing manually every few days as needed for ca and alk using Brightwells 2 part and needed to test and dose alk daily or it would drop below 7. Please dont make false claims just because your tank did not experience low alk, every tank is different. What works for one person or tank may not work for another.
Now if you already have a high demand for alk and already have a dosing system that keeps the tank stable then you may not notice/have alk issues.

It would drop unless you kept up your daily dosing...what did you think was going to happen? Are you saying that your alk consumption stopped because you added sand back? You said it yourself, if you have a high enough demand for alk and have a dosing system you wont notice alk issues...sand or not.

Large cuc is a bad idea. If it's just to remove the pest algae then removing them or most from the tank thats fine. You dont want all those snails and crabs to die after all the algae is gone. Here is what will happen. Add cuc, cuc eats most of the algae and you remove the rest with cleaning, nutrients issues is resolved leaving little algae growth, cuc dies releasing all the nutrients they consumed by eating the aglae back into the system, now you are right back where you started. Removing the cuc after the issue is resolved not only prevents their death but removes the nutrients from the system. Keep only what your system can sustain, for 100g reef I would have under 20 snails and maybe 5-10 hermits total, 1-2 emerald crabs and a few tangs. The 1-2 snails per gallon rule is way to many.

Im really not trying to pick on you here but adding a large CUC isn't going to resolve nutrient issues. A large CUC can certainly help control algae from said nutrients, but algae will continue to grow and come back until nutrients are better handled. Algae>Snails>Snail Poop>Nutrients back into the tank unless removed by proper maintenance.
 
I have done both. started with sand, then restarted with bare bottom.
now I just restarted and went back to sand (aragonite).
from my experience, the bare bottom only looks nice at first, in a few months, or years, it will be harder to keep it clean and in my case, after like 5 years, the bottom is just filled with crap that is ugly and impossible to clean. Mostly thick coralines and calcium build ups and lots of sand like particles (I assume this are calcium precipitate).
I would not go back to bare bottom.
 
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