Preventing anaerobic areas in a planted sand tank?

[suziq]

Let me just tell ya about my tank and you let me know if I should be worried and what I can do about it ;)

i have a 75g tank that is moderately planted. In order to compromise with my boyfriend (who paid for everything :p I have a estes blask sand substrate with each of my bulb or large roots plants in a nylon sock filled with flourite. I know it seems strange but they seem extremely healthy, the sand is pristine, and they are easy to rearrange this way! I also have extensive rock work and driftwood.

Since I have extensive rock work, i placed ceiling eggcrate on the bottom to ditribute the rock weight, put in my rocks, wood, and plants and then covered it all with the black sand.From glass bottom to top surface is about 3" of sand.

Now, months after I started, i am rethinking these ideas.
I can stir the sand that is around my plants and in the open BUT what about the sand that is in between the eggcrate and under the rocks?

i know that eggcrate is a common practice but how do you not develop anaerobic pockets? Or am i worriing for nothing :rolleyes:

p.s. I have noticed that on some of my larger plants that if I press on the root system, that large bubbles often come out. Is this normal for some plants?

[OrionGirl]

My understanding of anaerobic pockets isn't the widest, so wait and see what others say, but I think you should be okay. Any substrate can develop these pockets if not regularly disturbed. Once developed, you don't know about them and they cause no problems, if left alone. Additional bacteria grow that break down the nasties. The problem comes when you disturb the pocket, preventing the new bacteria from processing the toxins. The problem isn't that they develop, it's that they get disturbed. Since you can't disturb the sand within the egg crates, any pockets that develop should be processed and not released.

I think the bubbles around your roots is the result of air trapped in the nylon, rather than anything else. It should eventually stop. Bubbling from the leaves is normal--just a sign of happy plants.

[suziq]

Thanks OG. That makes sense.

OK another brain teaser for ya: Do any plants produce oil? I get a oil film on the top of my tank a few days after cleaning. I have a powerehead to break the surface and allow gas exchange. This has never caused any problems and I suck it off with the python every water change. I have come to 2 conclusions. one of my plants is making it or the more likely, it is coming from my food. I feed a variety but it is all comerially made and don't have this issue in m other tanks. HMMM....

[latazyo]

if you like loaches, you could get them

my kuhlis literally bury themselves in the substrate, they'd keep your sand stirred up to avoid anaerobics

[OrionGirl]

Doubt your plants are producing oils. Some kinds can, but I didn't see any you listed that would. Since it's following a cleaning, it's possible that it's coming off of your skin as you work in the tank. More likely, it is something a bit different in this tank and your foods. I've never had the problem in a FW system, but SW systems sometimes have the same problem. Increasing the surface agitation or getting a s surface skimming filter are the best bets...I'd probably ignore it. Or maybe add some floating plants (duckweed, water lettuce) that would suck up anything pretty quick.

On the loaches--kuhli's don't bury themselves deeply, in most cases. I have kuhli's in a tank with sand, and they've managed to dig into the laterise under the sand, but only in a few places. I wouldn't rely on them to prevent an anaerobic spot.

[wetmanNY]

The oil is a natural lipid layer-- but why it forms in one tank and not in another that seems pretty similar... dunno. At filter cleanings, I drag paper towel across the surface before I switch the filter back on.

I think anaerobic layers are perfectly natural in substrates. Only the deepest, completely anoxic layers enriched with food and detritus, are at all likely to overwhelm their sulfide-oxidizing bacterial neighbors and start a sulfuretum.

There's some discussion and links at www.skepticalaquarist.com ...not everyone sees it the same way however...

[latazyo]

try freshwater clams then

they'll get down there

[125gJoe]

Originally posted by OrionGirl
Since it's following a cleaning, it's possible that it's coming off of your skin as you work in the tank. And...it's possible it could be deodorant - that is if you reach in your tank far enough. Weird, but true.. :eek:

[suziq]

It doesn't show up right after cleaning. It is usually 2-3 days later or 4 days before cleaning. Howver you want to look at it, I do my cleaning usually every Sunday.
I am also very careful to not get anything in the tank i either shower before and don't moisturize or I rinse my arms really well before ever putting them in the tank.

I also rinse out the python with HOT water after I draw the oil out so when i fill, I'm not just putting it back. It has to be equipment, plants, fish, or food that is causingthis.
Here is m plant list: 1rubin sword, 2 amazon sword, red ludwigia, sunset hydro, moneywort, sagitaria lace, madagascar lace and red tiger lotus.

Any other ideas that aren't related to personal hygene?
:D

[125gJoe]

Originally posted by suziq


Any other ideas that aren't related to personal hygene?
:D

LOL

:D

[plantbrain]

I've found flourite and onyx to be great. I've never had them ever go anaerobic and produce the blackened stinky H2S smell.

Basic preparation:
I used about 150lbs for my 75 gallon tank.
You can get away with less. Maybe 100lbs or so.
I rinse it 3-4 times good then add it. I first add about 1/2 inch or so and then add 4 good handfuls of ground peat moss. You can get this at a nursery. I add add to this bottom layer a bunch of vacuumed mulm from an established tank. Ask the LFS or a friend who has a tank to let you vacuum their tank and get the dirt. Get as much dirt/mulm/detritus as you can.
Let the bucket sit for about 5 minutes or so.
Decant off the water.
Save the dirt.
Add about 1-2 liters worth of soupy dirt to this bottom layer. This is mainly organic material and is seriously loaded with bacteria. Save a bit for the filter.
You can also use some of the water from another tank, or run your filter on a friend's or LFS's tank for a couple of weeks first.

Thant's about the best substrate you'll get in the USA. Onyx and flourite can be had on line for about 12$ a bag of 15 lbs. Sometimes less. Shipping sometimes gets ya.
If you were in CA, I have 60lbs for sale or anyone that's interested can have at it. I am not shipping it though!
Regards,
Tom Barr

[aquascaper]

You can always get Malaysian Trumpet Snails if you want to move the substrate around. These snails are considered beneficial in a planted tank as they burrow themselves in the substrate in the day time and surface in the night.

I have a bunch of them in my tank and I always see them burrowing themselves under my flourite.

[plantbrain]

Those MTS's only move perhaps the top 1 inch at best.
Cory cats can do a bit of this also.

Horseface loaches are perhaps the best substrate movers that doesn't uproot plants drastically and move large amounts of gravel.


Regards,
Tom Barr