Sand bed to barebottom - why?

[Palting]

I am directing this question specifically to those that had a sandbed and decided to go barebottom.

A little background. My tank has a 2" aragonite substrate, and started 7 months ago, and is just starting to look really good. I met a guy who owns an LFS and maintains tanks who, I would have to say, is a barebottom with 100% water change advocate. To him, even a 1" substrate is DANGEROUS. Scared me, to say the least. Not sure I want to upsaet my young but maturing tank, however.

So, I'm asking this forum of knowledgeable and unbiased people what they're experiences are.
1. What was your substarate before you went barebottom?
2. Did you have an incident that lead to going barebottom, or was it just new knowledge?
3. How did the change go?
4. How is your tank now relative to the previous?

Thank you all very much for any response!!

 

[TripleT]

is a barebottom with 100% water change advocate

Does he also scrub his fish clean during water changes?

I've had a 1-2" sandbed for 15+ years. I like the look, and it's kept clean by good flow, pods, bristleworms, and a sleeper goby.

100% water changes are most sensible when a toxin has been introduced to a system. Outside of that, I'm not sure the risk is worth the reward. And I wouldn't recommend it for anybody new to the hobby.

 

[Palting]

Does he also scrub his fish clean during water changes?

I've had a 1-2" sandbed for 15+ years. I like the look, and it's kept clean by good flow, pods, bristleworms, and a sleeper goby.

100% water changes are most sensible when a toxin has been introduced to a system. Outside of that, I'm not sure the risk is worth the reward. And I wouldn't recommend it for anybody new to the hobby.

LOL!! Thanks for the response, triple T. It might have been a sales pitch, but maybe not since there have been rumblings about sandbeds lately. That's why I'm asking here.

 

[lordofthereef]

If I had to venture a guess he is running a heavily stocked SPS grow out system? I think it is far easier to have a control on nutrients with bare bottom. Don't confuse what I said here with thinking it is not possible to do so in a system with substrate, but huge water changes like that on a BB system is a little bit like "insurance".

 

[Palting]

Yup, he does have tons of SPS and frag tanks. If I understand his technique, IMO he basically just keeps the salwater new, with all the appropriate minerals, all the time by constantly replacing it.

 

[nemosworld]

That is a very costly measure, one that was replaced by calcium reactors and or dosing kalk. it's a good idea to keep up with water changes, 10 percent per week. sounds more ideal. I have met a very experienced reefer with a sps dominated system who only do monthly water changes and run his skimmer on 12 hr schedules. we he does a water change he only changes the water in his sump, all of it.

 

[sirreal63]

I can see some of his points...after all there is no sand on a reef and who wants all of those dentrivores, bacteria, microfauna and such consuming nutrients in a closed system? Oh wait...there is sand in the ocean and we actually do want something to help consume excess nutrients. The ocean is a closed system too, just on a much larger scale.

The problem with sand is depth and holding more nutrients than can be consumed and the possibly of rapid release of nutrients. 1-2" of sand in the display is a good thing. I have done both BB and sand, I will choose sand every time. You can run a tank with or without sand, different methods but both work. Both can be dangerous and both can be safe. There are no absolutes here, just different methodologies. It all comes down to preference and husbandry.

The 100% water is not a good idea for a home system, of course it is possible to do it and have everything live but freshly mixed saltwater can be harsh and there is no reason to do that.

 

[reefgeezer]

I started with a 5" + sand bed in the display. Reduced it incrementally as I started to battle pH problems. I eventually ended up with a bare bottom so I could have a crap load of flow in the tank without worring about sand flying everywhere. The DSB in now in a bucket. That being said, if you don't need a crap load of flow, a couple of inches doesn't hurt anything if you like the look and are willing to vacuum it regularly.

As to 100% water changes...
Unless done on an almost continuous basis, IMO, the stress created would outweigh the benifits. It does sell a lot of salt though.

 

[lordofthereef]

Yup, he does have tons of SPS and frag tanks. If I understand his technique, IMO he basically just keeps the salwater new, with all the appropriate minerals, all the time by constantly replacing it.

This is what I was suspecting. All in all I don't see this as being that costly for an LFS. Reason being is they can just use the waste water for filling their fish systems. Basically, what is waste for the SPS frag/growth tank is more than acceptable for the fish systems. I wouldn't go as far as to feel like this is something necessary in our at home systems. These measures just allow this guy to cross a few things off the list should they go wrong. He can certainly eliminate excess nutrients as reasons for potential failure.

 

[lordofthereef]

I started with a 5" + sand bed in the display. Reduced it incrementally as I started to battle pH problems.

As to 100% water changes...
Unless done on an almost continuous basis, IMO, the stress created would outweigh the benifits. It does sell a lot of salt though.

How were pH problems solved by removing sand?

As far as stress is concerned, wild SPS often spend time fully out of water during low tides. I would think that would provide far more stress than a full water change. Waer changes don't need to provide stress at all provided they are executed by matching parameters.

 

[Palting]

Thanks for the replies, all.

Same questions remain as in the first post, though. Thanks reefgeezer and Triple T. Anyone else with substrate to barebottom experience, or long term success with shallow sand bed, or catastrophes with shallow sand bed, with tips for the slightly anxious maturing noob? Thanks again!

 

[Stuart60611]

Well, I have some views on this topic. I believe that any sandbed less than 4 inches is going to negatively to at best neutrally affect the system in terms of nutrient/bio load. A sandbed less than 4 inches will not serve as a means of denitrification or nitrification and instead will just trap organic material and thereby serve as a potential nutrient sink. Yes, you can mitigate (in theory to neutrality) the negative effects a sandbed of less than 4 inches has as a nutrient trap through regular vacuming and stiring and ample fish and inverts to eat the organic debris and stir the sand. The best you can, however, hope to achieve with manual maintenance, fish, and inverts is that the sandbed is maintaned clean enough not to negatively leach nutrients back in the system because a less than 4 inch sandbed is not deep enough to serve as a means of nitrification and denitrification achieveable in a deep sandbed. This means that everything traped in a sandbed of less than 4 inches rots in the sandbed and is not broken down therein unless manually removed or consumed by inverts. In most systems (even those well maintained with excellent invert populations), complete neutrality is unable to be achieved, and the less than 4 inch sandbed serves as a nutrient sink to some degree negatively contributing to the system's nutrient load.

As such, if you feel you want to have a sandbed for asthetics and do not want to have a deep sandbed of 4 or more inches, I suggest you have as shallow as sandbed as you can at about 1/4 inch so as to trap as little organic debris as possible. This way you get the benefits visually while minimizing the potential negatives as best as possible. IME, many systems are plagued by having sandbeds in the 2 or 3 inch level which over time accumulate massive amounts of organic debris and provide the fuel for nusiance algae infestations.

 

[reefgeezer]

How were pH problems solved by removing sand?

As far as stress is concerned, wild SPS often spend time fully out of water during low tides. I would think ...

Sulfuric acid can form when DSBs don't perform properly. It is usually caused by not enough flow near the surface of the sand and excessive trapped organics. I had both.

Are you implying that all SPS corals can handle change without stress because a few have evolved to thrive in harsh conditions?

 

[Palting]

OK, all. I think I've agonized over this long enough. I looked at this year and the past year's Tank of the Month. They are dominated by tanks with substrates. Combinations of deep and shallow sandbeds. Granted, most of these are fancy set-ups with all the bells and whistles I can only dream about, but I think there is enough here that I will keep my 2" sandbed.

Thanks again to everyone for the input.