Do you have a bare bottom?

[georgiajams]

I was discussing customer's tanks with Bobby at CBA. Surprisingly, he mentioned that I was one of the few around town, that he knew of, that had a bare bottom tank. Both of mine are BB, but the 40B has about a 5-6 in sandbed in the refugium.

Just wondering who else has 'em. Come on, show us your bare bottom . Uhhh... well... at least your tank's bare bottom.

[h2ohno]

My tank is bare bottom. I use it for detritus collection. Pods of all sorts love it. Do keep in mind that my nitrates register 0mg/l. Tests do not turn pink they stay clear.

[goodfortune]

Hello, and welcome to Atlanta Reef Club's (ARC) TRT forum

What are you using to reduce nitrates? A 'fuge? Remote DSB? Light fish stocking and feeding?

I look forward to your input!

- Michael

Originally Posted by h2ohno

My tank is bare bottom. I use it for detritus collection. Pods of all sorts love it. Do keep in mind that my nitrates register 0mg/l. Tests do not turn pink they stay clear.

[Markv]

The key with barebottom tanks is to have a strong skimmer to remove detrital matter before it breaks down into nitrate and phosphate. To do this, the skimmer has to be run fairly wet. A lot of the 'starboard' style reefs, which seems to be the new trendy method, are simply modern day Berlin style reefs. The key word being modern; Berlin style, but with the newer skimmers and stronger lighting that is available today. These tanks also use the sump as a detritus settling area. They do frequent water changes to siphon up detritus off the tank and sump floor.

I ran my latest tank berlin-style for just under a year, but I got sick of not being able to reach the bottom of my deep tank. Plus it looked too stark for me. So I went even more old school than DSB, I went with a plenum and crushed coral(true jaubert). The reason for this is two fold, I can siphon the substrate above a plenum without deleterious effects and I can use a much larger amount of current with the larger/heavier grain size used with a plenum. With a DSB, the grain size is usually so tiny, that siphoning and strong current are problematic.

[goodfortune]

Thanks Mark!

From what I've heard, the Jaubert system helps significantly with supplying Ca and dKH, as well as nitrate reduction, due to the depth of the sand, and also the low pH and low dissolved oxygen in the water space underneath the sandbed.

I've also heard that plenum systems are crash prone. I'm guessing it has something to do with how much waste the sandbed can assimilate, or the reduction in sand bed volume due to it supplying Ca and Alk.

Am I on target with what I'm saying? If so, is there anything that you are doing in the care of your tank to reduce the likelihood of it crashing?

I look forward to you comments as well!

- Michael

[Markv]

Plenums were problematic for most US reefers, because they were instructed to set them up improperly. This mis-information was driven my companies and individuals that were trying to make a buck. For instance, the correct substrate for a plenum is crushed coral, but most places recommend something finer, such as special grade by Caribsea.

To be honest, DSB's are much much more crash prone. When my last reef hit the 4 year mark, I suffered the commonly mentioned Old tank syndrome. I'm done with DSB's. Plus, if you ever try to stir up a DSB to remove detritus, you'll have a mess on your hands. It's also next to impossible to siphon a DSB, due to the light and small nature of the grains. You end up siphoning the sand along with the detritus.

The nice thing about a plenum, is that I can occasionally vacuum the top layer of crushed coral. This is usefull, since no matter how alive a sand bed is... the detritus will build up.

Plenums are not maintenance free, like the way DSB's advocate. Another thing to keep in mind with plenums, they do best with minimal live rock and lower bioload. Heavy feeding is not a good thing for a plenum, and a lot of live rock will cover too much of the substrate. If you want lots of fish, go barebottom with heavy skimming.

[georgiajams]

Note that I wouldn't consider most of the sand beds I see of having enough depth to actually reduce nitrates, as is frequently alleged. I guess what the "proper" depth should be for reducing nitrates is controversial though. I don't want to put words in Bobby's mouth, but it seemed that he has had good luck with BB tanks as well.

My BB tank currently has no nitrates either. Had a small problem with them for a little bit, but they went away. Don't quite know what to attribute it to exactly. So, purely from my own experence BB works. By no means are they "necessary" as many would have you believe.

[Daytona955]

Actually there was a recent article in on eof the reef magazines I read that siad that they have recently found that the majority of the benifit from DSB's actually take place in the top 1-2 inches. They found that the remaining XX inches really did a very minor amount of the actual filtering. If I am not incorrect they said that 1-2 inches was fine and the 6 inch DSB's that were popular when the system first came about had little to no benifit.

[georgiajams]

What I always wondered is if you have a 1-2 in sand bed, is that a "deep sand bed"? What is "deep" anyway. And from what I understand, depth is just a rule of thumb anyway. That is, it also depends on other factors such as the granule size, etc.

I think we can all find articles that support alot of different positions on what depth of a sand bed to have. All I can say is that having no sand also "works".

[MyReef]

For more reading here are some pics and other info on bare bottom tanks...
http://www.reefcentral.com/forums/sh...hreadid=477421

[matlet]

I keep a pseudo-bare-bottomed tank with 1/4" of aragonite covering the floor in front of my reef. Under and behind the reef is bare. There is just enough to cover my sand-sifting starfish, who keeps everything very clean.

I have 3 fish in 75 gallons and I am slowly building up corals via frag purchasdes. No problems so far.

Mark T.

[mantisshrimp]

I switched to a bare bottom a little over a month ago,and I love it. I could not get my nitrates to drop to zero until I removed all the sand, and I have a Euro-reef. This is with one small Lawnmower blenny as the only bioload. I haven't done a water change since, all readings are at 0 still.

[Krux]

I'm not really local to you, but several of over here in Portland have made the switch.

Here is my overcrowded 75 gallon frag grow out system (dreaming of something bigger, so I call it that to remain optomistic!)

[kayaker97321]

I am currently switching to BB. I saw some local BB tanks and will never go back to DSB. Here is my new BB sandbed.








Krux's tank was the one that made me change my mind about BB tanks.

It's completely algae free. Place a new frag in it with a bit of algae on it and it is picked clean

Tyler

[kbxiong67]

Yeah i switched my nano to bb as well. I think my red head goby dug itself into the sand and died. I couldn't find him ANYWHERE! I waited for about a week...man my take broke out with red algae. I vaacum it but within hours...it forms a layer over the sand and some rocks....they were also starting to over take some of my corals. So I ditched the sand bed and no more algae. =) I"ll probably put a light layer of sand just for looks.