DSB...Let's Discuss!

[NaH2O]

What a great group we have here. I knew all of my practice of sitting in the front row of lectures and note taking would pay off!! Scott, I'm glad I could help. Just sit behind me and to the left during exam time.

Originally posted by mojoreef
A DSB will NOT crash your tank, thats not the way it works. It will simply cease to function as a filter.

I think this basically sums it up. On another similar note, will live rock ever cease as a filter (i.e. when covered in coralline)?

[mojoreef]

Don't give me any credit. It was completely a case of flying by the seat of my pantaloons. Dumb luck I tell you!

Exactly Craig, just like falling off a log, rofl

I would be intently listening to Mike's deep theories nodding in agreement, and taking indepth notes, while Scott is looking over my shoulder. I keep trying to block his view of my papers, but to no avail....."don't worry Scott, I'll make copies for you".

Oh yea and Mike standing in front of everyone would get stage fright and just stare back at you with a dumb look on my face

I think this basically sums it up. On another similar note, will live rock ever cease as a filter (i.e. when covered in coralline)?

No of the filling, since the rock has no bottom and bacterial tugor actually will shed the detritus. BUT on the phosphate it still has its issue, but the corraline sure loves it.


Mike

[Dakota]

Ok so a remote dsb won't work becuase it needs food to keep it going now you don't want to feed seperatley because this is adding nutrients to the system? but the remote bed won't work becuase you can't get the detrius from show tank down to it? now if you put in spray bar at bottom of bare bottom tank and keep detrius in suppension until it makes it to overflows would this not then feed the sand bed? this way you can take sandbed offline and replace as nessecary. if we are worried about sandbed leaching nutrients back why can't we say add a mangrove, macroalgea, refuge down stream from bed and maybe make water flow through phosban, or rowaphos after refuge and before going back into main tank Would any of this work or am i just not thinking

[NaH2O]

No, you ARE thinking. The remote DSB would work, IMO, if you kept flow so that detritius would make it in there. I also feel that food particles would make there way in it, so you wouldn't have to "feed separately". You will get denitrification. There are a few people, that I know of, that will have a remote sand bed, specifically to be able to take off-line and replace the sand. Good question about the mangroves, as I'm not sure how much more nutrients they utilize in comparison to macroalgaes.

If anyone disagrees, please let me know....

[mojoreef]

Hi Dakota. The quotes I posted are those of Dr. Ron Shimrik, not mine. My tank is bare bottom and plumbed in the manner close to what you discribe, and the detritus is removed quite well. I think it would be easy to plumb a tank to do what you say. having a remote dsb and loading it with calurpa would help in getting rid of some of the nutrients. although calurpa/macros or not the most efficient thier is a net gain for sure. Mangroves would be great because the roots go into the bed where the nutrients really are but they are very slow growers, and arent very quick when it comes to uptake ammounts.

MIke

[NaH2O]

Mike, what is your opinion on having live rock rest on PVC instead of the sand bed? Do you think there would be the same types of dead spots as if the rock rested on the sand? I was planning on having the rock rest on PVC (set up like pylons in the sand)...not a rack, per se, but elevated off the sand ever so slightly. I thought that it may allow for some flow under the rock.

Oh yea and Mike standing in front of everyone would get stage fright and just stare back at you with a dumb look on my face

BTW, I would be the only one paying attention anyway in our little conference, and I'd be scribbling down notes the whole time, so no one would be staring at you

[Dakota]

Mike I was just making a blanket statement, not to blame anyone or point any fingers. The system i discribed is one that i am thinking of doing on a 90 gallon tank with say a 50-60 gallon sump, thought of kinda a redundent system mangrove first in line then the macro's then try to get the rest with phosphate sponges maybe do tank turnover 30 times or so? maybe a closed loop . turkey blast the rocks coupole times a week to remove any particles NaH20 i currently have a pvc rack supporting my rock. before i did this i had a major build up of detrius behind and around the rocks even with 20 times tank turn over hr. now i only have some detrius in a section not getting enough flow for whatever reason. but it is in the front so easy to syphon off.Mike what do you think of doing a teired sandbed of multiple levels to increase surface area? excuse ignorance but what is "optimum" depth of a dsb.

[mojoreef]

Mike, what is your opinion on having live rock rest on PVC instead of the sand bed? Do you think there would be the same types of dead spots as if the rock rested on the sand? I was planning on having the rock rest on PVC (set up like pylons in the sand)...not a rack, per se, but elevated off the sand ever so slightly. I thought that it may allow for some flow under the rock.

yep When I had a DSB that is he way I did it, racking though. Then I atached a pump and a PH so water would blow up into the rock. You just have to watch for detrtus build up.

Dakota the system discribed is exactly what I was doing on this tank set up when I first set it up. I will post pictures below for you. If I understand your system you are talking about a high energy main tank with BB so you can maintain good flow, then using remote DSB and macro tank for added filtration?? is that what you are saying.

mike

[Cougra]

I was thinking about other ways to remove dead spots in the sandbed to help prevent the formation of Hydrogen sulfer gas and was wondering if it would be benificial to have a burried low powered heating cable similar to the ones that are used in Dutch Style heavily planted tanks.

The purpose of the heating cable is to heat up the water in the sand bed a couple degrees warmer then the rest of the tank. This creates small convection currents. The slightly warmer water will rise and as it rises the colder water will go to the bottom of the tank.

The water movement will naturally be slow so it would still be able to support both aerobic and anaerobic zones but there would be less chance of having dead zones within the sandbed. It would also be more reliable then depending on a natural life cycle and creatures to keep the water flowing throughout the sandbed.

[mojoreef]

you bring up an interesting point michelle. I have heard this before from Harker and I believe Moe. The possibility is thier however to not get dead spots the heater wires would have to be very extensive. I have also heard of a heating mat under the tank (rubber kind). Sulfer gas I dont believe is a problem although it does happen from time to time. if you have an anaerobic zone you will have sulfur reducing bacteria, so it does not go to defeat the problem. It may however be an option for those that wish to run a dsb and as better method of migration of nutrients, that way you are not so relient on bugs.
The main problem (for me anyway) Michelle is that the dsb system does not export (beyond a small ammount of nitrogen based products) this leaves all other products to stay in the bed, and thus eventuly build and fill. Although what you are saying would be a benefit, what we really need to find is a way for the dsb to export and a way to deal with P.

good post


Mike

[zy112]

this has been a great thread and i'd like to thank everbody who has contributed b/c i have learned more about dsb's than i ever thought i would want to. i have a question. personally, i like the look of a sb, so is better(not harmful) to have like a 2" SB?

[cleartank]

I love the look of a 1" or 2" of sandbed regardless of whether it works or not; a DSB is an eyesore to me.

[mojoreef]

Cleartank I also like the look of a nice white sand bed also, not a big fan of looking at 6 inchs of it on the glass, but I do love the look on the bottom.

Zy112, a dsb, if 6 inches or 2 has all the same goods and the same bads. The reason your hearing alot about 2 inch beds now is that mos of the experts have conceded that you can have a good anaerobic zone with 2 inches of sand, thus denitrification. However if you look at how the dsb biological system works, it will have all the same problems and probibly wont last as long as a 6 inch one. Now if you were to stir the bed and clean out the detritus, you might have better luck, but that is a sloppy job to do every few weeks.


MIke

[NaH2O]

Since I had printed this thread for a little light reading today, I was reminded of a few issues brought out on phosphates. If you followed along on this thread, you would have found that Cougra was having algae problems that were thought to be from her DSB. I decided it would only be right to put a link to Cougra's thread on her issues. If you are interested, here is a link to her thread and what was discovered: Hair Algae - ARGH! (long post)

[LaquitaWilliams]

ok...just read the whole thread....one thing about heating wires or mats under the tank, i've seen heating mats for use with reptile tanks that go under the tanks...if someone is looking to try this....however, i don't think you can control the temp on those....

i flunked chemistry in high school ...but i've been trying to understand chemistry more lately now that i have a reeftank...specifically phosphates..

a few things i've read:

every living thing needs phosphates to survive...
there are many types of phosphates and phosphates bind with many different things...
hobby test kits really test for the wrong type of phosphates...


even if the bed is leaching phosphates, i wonder how much would be consumed by a decent skimmer??
as of right now, i think i understand phosphates as well as i understand black holes....i know they exist...i know they can suck...i know they're everywhere....but if someone asked me "what exactly are phosphates?"....i think my answer would suck..

i know i could benefit from some basic phosphate understanding...someone should research this and spoon feed it to me