Is there something wrong with my sand?

[lwkimbley]

I have zoos, a huge trumpet, a bta, and several 2 inch maxima clams and I can't figure out these bumble bee snails and Strawberry crabs. Any snails I have placed in the tank just sit on the sand bed with there mouths extended. I move them to my 20 gallon hospital tank and they slide accross the sand like they are ice skating. I have a 5 inch deep sand bed. 3 inches of pool filter sand and 2 inches of live sand. Could there be any problems with my sand bed?
Ammonia 0ppm
Nitrites 0ppm
Nitrates 0ppm
PH 8.4
Salinity 1.023
Temp 79-80 degrees F
mag 1320
cal 400
alkalinity (on my test kit there is a colored bar) Normal

[Reefland]

I don't think it's a sand problem; it's a snail problem. Bumble Bee snails are not tropical snails, they come from cooler water and will not live in our tropical reefs with 80 degree temperatures. Additionally, snails need a slow acclimation to avoid osmotic shock. If you are just placing them in your tank with no acclimation, this could be the problem.

[Ninong]

Bumble Bee snails are not tropical snails, they come from cooler water and will not live in our tropical reefs with 80 degree temperatures.

Scott,

I think you're confusing Bumble Bee snails with Margarita snails.

Bumble Bee snails are tropical. The reason that some people do not recommend them for reef aquaria has to do with the fact that they are sometimes predatory on other snails and they will consume some of the good wormy critters in your sand bed, assuming you actually have a sand bed. ;;

This is what they look like: http://www.liveaquaria.com/product/p...cfm?pCatId=565

[Reefland]

Dang it, guess I didn't wake up yet. The funny thing is I just did a bunch of research on them both, just got them mixed up.

[lwkimbley]

Could I have sulfur in the DSB? I do not smell any egg or abnormal odors. My Phosphate is also within limits! The sand in my hospital tank is the same as my main tank. However, The crabs and the snails (Astera) just lay there in the tank for days. Within less than an hour they are scooting all over the tank in the 20gallon hospital tank. I got the stawberry legged crabs and Astera snails to keep the sand white. I also have 3 tigertail sea cucumbers, 1 diamond goby and a lawnmower blenny (for the Madien Hair I placed in my tank prior to having a refugium)! Oh by the way the Maiden Hair is beautiful. The tangs had a constant source of greens and it digest Nitrates. The tangs got tired of it and switched to seaweed and Broccoli.

[Ninong]

Could I have sulfur in the DSB?

Sure. My DSB is 6"-7" deep and I certainly expect that I have some anoxic pockets down there somewhere.

In the very top layer of your sand bed oxygen is readily available and aerobic respiration dominates. This layer can vary in thickness from less than 1 cm to 4 cm, depending on conditions. The boundary between this upper layer where oxygen dominates respiration and the next layer where nitrate dominates is called the RDL (redox discontinuity layer). The upper layer is an aerobic environment and then once oxygen is sufficiently depleted, you have an anaerobic environment -- which simply means "unable to support aerobic respiration."

Decomposition in the upper layer is oxidizing and in the anaerobic layer it is reducing. Once you get down to the point where oxygen is completely undetectable, you have an anoxic environment. Anoxic simply means lacking oxygen.

As available oxygen decreases, nitrate (NO3) reduction becomes the most favorable respiratory pathway. This layer is usually only 1-2 cm thick. As the redox potential decreases to zero (oxygen is undetectable), sulfate (SO4) and carbonate (mostly CO2) reduction becomes the dominant metabolic pathway over the next 10-50 cm. In healthy, well-flushed natural marine environments, the redox potential reaches zero within the first 6-10 cm depth.

If you are going to run with a 5" DSB, you need to keep it healthy to avoid potential problems. You might want to read up on exactly how a deep sand bed functions and what you need to do to keep it functioning:

How Sand Beds Really Work: http://reefkeeping.com/issues/2003-0...ture/index.htm

How a Deep Sand Bed Can Produce Food for Reef Inhabitants: http://www.dtplankton.com/sandbeds.htm

Muddy Waters: http://web.archive.org/web/200208060.../1/default.asp

I do not smell any egg or abnormal odors.

You won't smell any egg or abnormal odors unless you dig up your entire sand bed. Any hydrogen sulfide would be converted to sulfate as it passed through the oxygenated layers of your sand bed. You're not going to smell anything unless you deliberately turn over your entire sand bed.

I have a 5 inch deep sand bed. 3 inches of pool filter sand and 2 inches of live sand.

What exactly is "pool filter sand?" Is that just a fine particle SiO2 sand? Do you know the exact chemical composition?

My Phosphate is also within limits!

I take it "within limits" means less than 0.01 ppm, right? Certainly less than 0.03 ppm. Anything higher than that would not be considered "within limits."

[lwkimbley]

Yes the pool sand is SiO2. It seemed like a great base for the deoxygenated zone. I have a degree in Environmental Science and have set up trickle beds for Waste Water systems. We used large grain Sio2 then medium lastly fine grain. This creates the Aerobic and Anarobic areas to break down large solids and transfer Ammonia to nitrite to Nitrate to Nitrogen Gas. Then the Water was reoxygenated and finally we ran the water through ULV lights. Lastly we dumped it back into the rivers waste free. Isnt this what we are doing with the DSB and biological and Mechanical filtration. Our wastewater plants treated millions of gallons a day. I only have to treat 125 gallons.
My Phosphate kit only has a colored bar and my water is in the normal limits section?

[Ninong]

Yes the pool sand is SiO2.

Some hobbyists use SiO2 (quartz) sand in their reef aquaria. I have never used it but I know that it is used by others. One of the problems associated with using quartz sand is the possibility that it will not be pure. If it is contaminated with feldspar and other compounds that are more readily dissolved in saltwater, you could have problems with algae. Pure quartz is stable but some other silicate compounds can dissolve.

Here are pictures of aragonite (CaCO3) sand and quartz (SiO2) sand under 40x magnification: http://www.inlandreef.com/Testing/SandPhotos.html

It seemed like a great base for the deoxygenated zone. I have a degree in Environmental Science and have set up trickle beds for Waste Water systems.

Waste water treatment trickle beds were the inspiration for trickle filters in the marine aquarium hobby.

We used large grain Sio2 then medium lastly fine grain. This creates the Aerobic and Anarobic areas to break down large solids and transfer Ammonia to nitrite to Nitrate to Nitrogen Gas.

Natural filters for freshwater ponds are set up with different sizes of gravel, starting with rocks at the bottom and then large gravel on top of the rocks and then pea gravel on top of that. The water enters underneath the filtration bed and percolates up through the layers until it flows through the pea gravel at the surface and then overflows back into the pond. So I guess that's just the opposite of the way they treat waste water.

Sand beds in reef aquaria can be set up in two different ways. One method is called the plenum method and it was pioneered by Dr. Jean Jaubert and the other method is simply a deep sand bed. The plenum method calls for a void beneath the gravel (sand) bed. This is an area of water with very low oxygen content that is about 3 cm thick. Above that is a mesh grid holding a layer of gravel (possibly crushed coral) that is about 4-5 cm thick and then there is a fine screen mesh between this gravel layer and the layer above it which is composed of slightly smaller gravel (large grain coral sand). The screen between the two layers is to keep burrowing animals from disturbing the lower layer. This method is usually called the Jaubert method and it is not the same as what we refer to as a DSB (deep sand bed).

A deep sand bed is a substrate that is usually composed of a mixture of relatively small particle sizes of aragonite sand, although it can be constructed using quartz sand of the appropriate size. It is not set up in layers of different size grains like a plenum system. The DSB relies on the action of the microscopic and macroscopic sand bed infauna to keep the sediments churning. Denitrification and detritus processing takes place in the DSB. If the DSB does not contain viable, reproducing populations of diverse infauna, it can go bad in various ways. It can start to solidify (clump) or it can reach a point where it is no longer processing waste but rather the waste is trapped in the sand bed.

The reason the DSB is not composed of different size layers has to do with the preferred habitat of the microfauna that will inhabit it and keep it going. That plus the fact that finer average particle sizes provide more surface area for bacterial colonization than larger particle sizes.

You can get a pretty good idea of exactly how deep sand beds function here: http://reefkeeping.com/issues/2003-0...ture/index.htm and http://www.dtplankton.com/sandbeds.htm and http://web.archive.org/web/200208060.../1/default.asp

Those articles by Dr. Ron Shimek should give you a good idea of what to look for in deciding whether you might have a problem with your present sand bed.

This article by Dr. Rob Toonen is a more detailed explanation of the chemical processes that take place in a deep sand bed: Part I: http://www.seabay.org/art_plenums_part1.htm and Part II: http://www.seabay.org/art_plenums_part2.htm

Then the Water was reoxygenated and finally we ran the water through ULV lights.

Shouldn't that be UVL?

Lastly we dumped it back into the rivers waste free. Isnt this what we are doing with the DSB and biological and Mechanical filtration.

The difference is that your waste water filtration bed is not part of the river where the fish swim.

My Phosphate kit only has a colored bar and my water is in the normal limits section?

Sounds like something designed for testing phosphate levels in freshwater tanks? Phosphate levels have to be kept very low in reef aquaria to avoid problems with nuisance algae. The test you are using is incapable of measuring the levels we are talking about.