Removing sand bed / going barebottom??

[jcm1229]

Ive had a 37g setup for about 3 years and the last 4-5months I've battled hair algae, cyano and I don't see much life in my bed. My water tests OK, but I think the 4-5 inch sand bed has got to go.

Should I go barebottom with 1/2 inch of decorative sand??

WHat type of sand???

Any comments/suggestions/tips etc ...??

 

[doc_slick]

There are several school of thought on this. I know of several people that are very successful with bare bottomed tanks. IMHO, I would not get rid of the sand. I have had several bouts with this as well. My tests revealed nominal results. I simply used a gravel vacuum and sucked up the cyano with a water change and added turbo snails right on top of the hair algae. Problem solved. I still get the cyano from time to time, and now have a crab that eats it.

 

[cdeakle]

I actually had a bare bottom tank for over a year at one point and I LOVED it. Maintenance was soooo easy and def solved my algae problem =)

If it wasnt for my cool starfish I would have went back but thats no longer an option for me.

 

[liquid]

There seems to be evidence based on real world systems that DSB's will become nutrient sinks and that over time they will actually leach back phosphates depending on changes in temperature, salinity, etc. This seems to happen after +3 or +4 yrs of having a DSB installed. IMO the jury's still out on this as I know a number of people that have DSB's that are 10-12 yrs old that never had problems. ::shrug::

I don't know if it happens w/ shallow beds or if it doesn't really matter. I'm watching the people that have converted away from DSB's to bare bottom tanks to see what their results are.

A sandbed of some sort sure does look nice tho in the bottom of a tak...

Shane

 

[Carpentersreef]

I had a bare bottom for the first few years, and changed over to a DSB. I want as low maintence system as possible.

I found that the detritus buildup with my bare bottom set-up was detrimental to my system, and my DSB now handles it fine. I've also put a deeper DSB in my sump. As far as long term nutrient sink problems, I'll probably just change my DSB if that ever starts to happen. Maybe "old tank syndrome" has something to do with the type of food/water/salt that was used over time, I don't know.

Mitch

 

[Quigonsean]

Maybe "old tank syndrome" has something to do with the type of food/water/salt that was used over time, I don't know.

That makes sense. I would also say maybe so does janitor crews, certain crabs/snails/stars/etc... eat detritus like no tomorrow, and some don't. If you got cleaners that tear up ditritus you may never develope this prob or it may take way longer. Just my 2cents. The history channel run all that stuff on JFK last week and forgot the greatest thing he ever did. The greatest thing he did was he did Marylin Monroe.

Sean

PS I know most of the abrieviations, but what does "FWIW" mean?

 

[Anonymous]

for what it's worth

 

[Quigonsean]

Thanks- BTW I just before checking back here read a post on cycle and stuff and it hit me like a 2 ton heavy thing but then it was used in context very well. However thank you.

Sean

 

[mountainbiker619]

I just went from DSB to starboard bottom. Needless to say, I love it and I can tell a big difference via my skimmer, it is not getting even close to pulling anything out.

 

[liquid]

Here's something I pondered while reading all those threads: why not cast the bottom out of something that gives the texture of a live rock base so that it looks like you're on a reef base and not a sandbed?

Shane

 

[jcm1229]

I'm planning on removing the sand, but can't get to it for a few months. Besides running carbon and phosphate sponge, more water changes and an addition of a lawnmower blenny, any other thoughts??

 

[Anonymous]

Here's something I pondered while reading all those threads: why not cast the bottom out of something that gives the texture of a live rock base so that it looks like you're on a reef base and not a sandbed?

Shane

Hey Shane,
Many public aquariums do this using fiberglass or even concrete. The results can be pretty cool, but it is relatively labor intensive, and takes considerable skill (especially with fiberglass). Then again, considering the work most people put into setting their systems up, I'd say it would be just another piece of the process pie.

Most people who have read around the boards know how I feel about using deep sandbed filtration, so I won't dispense my views any further. If any of you are interested in further reading and haven't already seen them, there are several extensive threads on reefcentral dealing with "DSB vs. barebottom" and the pros and cons of each.

 

[Anonymous]

Hey galleon!

Does anyone have any actual data on DSB or BB yet?

 

[reefman101]

I have had a tank that has been set up for 4 years. The feeding regime, lighting, and maintanance has remained constant. However, algae is becomming a big problem. I had a 3 inch sand bed. I removed most of the sand bed (I kept a small amount to reseed the bed) and washed it. I then replaced it in the tank. After 3 months it has not helped the algae problem. It is possible that washing does not remove phosphate bound to the sandbed

 

[Anonymous]

I have had a tank that has been set up for 4 years. The feeding regime, lighting, and maintanance has remained constant. However, algae is becomming a big problem. I had a 3 inch sand bed. I removed most of the sand bed (I kept a small amount to reseed the bed) and washed it. I then replaced it in the tank. After 3 months it has not helped the algae problem. It is possible that washing does not remove phosphate bound to the sandbed

And its possible that your algae problem is not do to the sandbed at all.

 

[liquid]

Righty: there's a lot of real world references to what happens to a sandbed in closed vs. open systems. The Florida black water event is a pretty good example from what I read of the references. If a closed system doesn't get a good flushing periodically (like from a hurricane or severe storm) nutrient levels build up (eutrophication) until the system can't hold anymore. Then algae and other problems become a problem.

Essentially what I took away from it was that if your nutrient import exceeds your export, your sandbed slowly increase its nutrient loading until it can't hold any more and then things start going bad (algae, etc). There's no real testing been done on sandbed depth or particle size vs. this phenomenon but the real world references have started to make me rethink a sandbed a bit. From what I took away from the threads I read was that once the sandbed plugs, it can (and will) release phosphates at the drop of a hat (i.e. changes in salinity, temperature, etc) and other possible things.

I'm almost wondering if this isn't what Shimek saw when his system started going into the crapper.

FWIW, I noticed in my 3 yr old system that coral just started dying for some reason. No matter how many waterchanges or how hard I skimmed the tank things just slowly withered. I recently moved my tank into a new tank and things have really perked up again. I have no data to discern what caused the problem to begin with but the only thing I changed from the one system to the other one was I replaced the sandbed w/ new sand and I used different lights (went from 1x250 watt Iwasaki 8 months old to 2x4' VHO 6500 K bulbs + 1x3' VHO actinic.) I'm using my IceCap 660 to push NO GE Daylight bulbs to near VHO light levels. My gut tells me that it was either my lighting or my sandbed or maybe it was something else. It's all anecdotal.

Shane

 

[Anonymous]

Hey galleon!

Does anyone have any actual data on DSB or BB yet?

Hey Righty,
If you're alluding to the ashing idea that Shane and I were throwing around a few months ago, to determine % organic composition of a DSB sample, it doesn't look like that study is going to develop any time soon. With a big thanks to Shane for doing the digging and finding the key paper, it turns out that the previously standard method of ashing for organics can give startlingly innaccurate and imprecise results. The method that is now in the process of being adopted is rather beyond the current capabilities of the labs I'm at, and where Shane is at as well.

 

[liquid]

Yep, ashing a sample can be off by almost a factor of 3x, otherwise this would have been a piece of cake to perform. The best way to do it includes using a Chromium IV compount which is a big PITA for disposal -- something I can't easily do at the company I work for.

Shane

 

[Unarce]

There's a great article in the 2004 Annual of Marine Fish and Reef magazine titled Benefits of Sand Beds. There are no charts showcasing data between DSB and BB, but it does make general references to scientific research. It addresses some of the assumptions that reefers make about depth and grain size.

For example: Nitrification and denitrification can take place at only a 0.08mm distance from eachother. Perhaps DSB's are overkill.

or

Many think that the smaller the grain, the larger the surface area. Only if every grain was a perfect sphere. Not the case when you take account of the surface roughness of larger grains.

An age-old discussion for reefkind. Personally, I've only utilized either BB or 1 to 2 inch sand beds. Luckily, I've been able to avoid algae problems. Phosphates and Old Tank Syndrome are very real threats caused by DSB's and I believe this should open many eyes.

 

[Anonymous]

Phosphates and Old Tank Syndrome are very real threats caused by DSB's and I believe this should open many eyes.

Phosphates and "OTS" are real threats, and are not caused only by DSB's. Any tank, with or without a sandbed, neglected the way most with DSB's have been will have problems.
My issue with this whole dsb/bb discussion is the simplified, incorrect idea that DSB=bad.
If by 'open many eyes' you mean people who have the set it and forget it mentality in regards to DSB's, I agree with you completely.