ammonia pockets under live rock?

[ToddinAtl]

Hi All,
I've had my system set up only 2 months. I followed the "How To's" here on the board. The relevant points are depth of the sand bed and live rock positioning. I have between 3-5 inches of arragonite with a topping of 40 lbs live sand. On top of this rests 100+# of LR. (stacked to reduce substrate contact as much as possible)

I visted a LFS last night and got the 5th degree by the owner. She stated that my system was going to crash at about the 6 month point because pockets of ammonia were going to build up beneth the LR and release. She advised taking out about 75% or the substrate, place the LR directly on the glass bottom and move the sand away from the rock. Then weekly vaccum the remaining sand to suck everything out.

This is the first I've heard of this. Have I made a mistake with my substrate depth? Has anyone experienced an ammonia spike that could be related to this? Does this look like a potential long term problem?

Thanks for the help, not only with this question but all the other ones I've had and will have!!!

Todd

 

[stilmas]

I've never heard of that either. First of all this person obviously promotes the Berlin method which is to have NO substrate and alot of live rock and heavy skimming. This method works, but is old. There are newer proven methods that work also, such as what you are doing with a DSB and live sand. Second of all, if you have sufficient biological filtration, the ammonia won't even come close to building up.Also, the live rock is a form of biological filtration and if ammonia builds up under the rock, the bacteria in the rock will consume it. I've been to many, many different LFS' and they all have something different to say about how my tank is set up. I found one LFS where they are very, very knowledgable and I only take his word on reefs and saltwater tanks out of all the stores I've been in. There may be some truth to what she is telling you, but I doubt it will happen as long as you have good water movement and biological filtration.

 

[mweber]

Don't listen to the LFS lady. Do a search on this board and read about DSB (deep sand beds). You are doing fine. Now all you have to do is not touch anything and wait about 8 more months.

 

[Tremelle]

If that is what the lfs person told then most of the people on this board are in for a rude awakening. Most of us who used substrate either have our live rock on top of the substrate or the substrage placed right up to and covering the bottom of the rock. I have not experienced an ammonia spike due to my rock being placed on the substrate. My tank has been set up for 2.5 years with no problems, except with Rio pumps.

 

[Mouse]

There are many ways to skin a cat. Sounds like the Lady at your LFS has only ever done it one way her whole life, & IMO would lead me to beleve that she doesn't know allot.

I went to an LFS in Kent in England. They had a complete Deltec system running in the shop, over £7000 pounds worth in my estimation (very nice cabinets). I had never seen such a shocking display of missmanagement in my life, it was the most hideous stinky pile i have ever seen excused for a reef. what made me laugh was the way the guy who owned the shop was telling people that he gives his advice for free. I can assure you that that advice was based heavily on what he happend to have in stock. Ignore her, listen to people on this board, they made a reefer out of me.

 

[Anemone]

Hmm,

Not only is this lady not up-to-date on current reefkeeping methods (especially vis-a-vis DSBs), but she's also mistaken in what she tried to tell you. I'm sure she meant to warn you about pockets of hydrogen sulfide (not ammonia) in your sand beneath your rocks. It's an old wive's tale describing tank wipeouts due to release of this noxious, rotten-egg smelling gas. Yes, it can be present in DSBs. No, it has not been found to harmful to our tanks.

Kevin

 

[stilmas]

Not to get off the subject, but speaking of LFS' that say they have healthy reefs when in actuality they are stinky piles of diatom, hair algae and cyano....Check this site out. http://www.aquaoceans.com/ This place is about 1 mile from my house. Let me tell you, don't believe what he puts on his site! His tanks are HORRID! I couldn't believe it when I went in there, I turned right around and walked out! There are few places like that that I had went into and heard the people speaking of their "display" tank. More like a septic tank instead of a reef tank. It's unbelievable that they call it a display. I'd be completely embarassed if it was my store, not a good way to sell yourself or your products if you ask me. If a store has these problems, I don't deal with them AT ALL! Maybe for something like salt mix or some other dry good if I need it fast and the place is close, but that's about it. And ya know, I feel real bad for the livestock in places like these cause their death rate must be incredibly high. I've been known to see a nice fish that looks like it will end up suffering in the end and I buy it to "save" it from certain death. I know it's risky to do, but I haven't had any problems in the past and don't do it since I started reefing. Don't want to jeopardize my investment which is becoming very expensive, I'm sure everyone here can relate to that!

[ November 14, 2001: Message edited by: stilmas ]</p>

 

[Anemone]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by ToddinAtl:
<strong>Thanks for the input, and yes I do trust the participants on this board over the LFS folks. I do have good filtration and I vaccum the sand bed during water changes, especially around the base of the rocks.</strong><hr></blockquote>

Well, I used to hydrovacuum my 2" of Crushed Coral (CC) substrate when I first started out (didn't know any better), but I haven't hydrovacuumed a tank in over 5 years (including the original tank that now has a 4" mix of CC and finer-grade sand).

If you've got CC, you'll need to hydrovacuum, as it is really the wrong grain size to support the majority of the DSB critters we depend upon to process detritus. However, if you've got a finer-grade, live sand bed, hydrovacuuming is counter productive, and the total disturbance of the oxygen "zones" that have developed will destroy the bacteria that processes nitrate (not to mention vaccuming out a lot of the micro and small macro critters who do the detrital processing for us).

SO, if you've got a crushed coral or some sort of large shell substrate, you need to keep hydrovacuuming it. If you've smaller grain sand at 2+" in depth, buy yourself a sand bed detrivore kit, and quit vacuuming!

Kevin

 

[ToddinAtl]

Thanks Kevin,
I was hoping someone would address the vaccuming issue. When doing water changes do I just want to take the water off the top? or vaccum the rock? And because I've seen 2 sides here on "sand stirring"..I will assume your point is to leave the sand alone?
Thanks Todd

 

[SPC]

Yes Todd let the sand do its thing without disturbing it. When I do a water change I blow the rocks off first and then siphon the suspended matter, or as much as I can get.
Steve

 

[ToddinAtl]

Thanks for the input, and yes I do trust the participants on this board over the LFS folks. I do have good filtration and I vaccum the sand bed during water changes, especially around the base of the rocks.

I think you're right Kevin...she did say ammonia..but she said one of her customers had experienced a wipe out and his wife was across the room and said it smelled like rotten-eggs.

I can't understand why she told me she has had to help people hundreds of times because of the DSB setup...She wasn't trying to sell me anything..Could these "other customers" been doing something wrong? I sure hope I'm not doing whatever they were...

Thanks again,
Todd