|Topic Review (Newest First)|
|01-04-2004 10:00 PM|
Ahhhh the trials and tribulations of opinions
Thanks guys, Now I have to go check my roots... BTW... beautiful photo Ghaz.
|01-04-2004 08:07 PM|
Originally Posted by Raul-7
|01-04-2004 07:57 PM|
|Scorpion||The dark color in the eco complete gives a nice contrast along with the plants...|
|01-04-2004 06:00 PM|
|Raul-7||Just a question, how long can you keep Eco-Complete as a substrate before it's cosidered depleted? Are you supposed to throw it away, or just respike with root tabs?|
|01-04-2004 12:34 PM|
Originally Posted by rasconza
|01-04-2004 10:56 AM|
It depends on how much organic matter is in your substrate and how compact the substrate gets. Decaying peat can be dangerous, too much unremoved leaf litter can be dangerous, and if you use fine granular sand, it will compact very easily becoming dangerous. Using garden soil, top soil, which may contain manure, leaf compost, worm castings, and other sources of high nitrogen can be dangerous for this reason.
Several years ago I used peat plates in my substrate, the kind you buy in pet stores. Within 8 months the peat turned jet black and was rotted. I had little bubbles of toxic gas coming up from the substrate. It smelled very foul, like rotten eggs. Plants in that area began to melt, and when I pulled them up the roots had turned black.
You can often get pockets of anerobic while the rest of the substrate remains fine. This is actually fairly normal. People say you can avoid this by churning up the gravel to prevent it from compacting, or by doing deep vacuming. Problem is that when you disturb the substrate, you unearth mulm and nasties into the water which can cloud the water, raise DOC, and bring out pollutants into the water. If you vacum you can remove fertilizers and additives such as laterite.
The best thing is to avoid using organic material in the substrate, do regular water changes and surface vacuming, and remove dead or damaged leaves from plants before they disintergrate into the substrate.
Some plants seem to actually do well in a anerobic substrate. Some Cryps.
Ghazanfar is obviously not growing large swords, Crinums, or Nymphae! These are deep rooting plants with massive root systems. With large plants, you need a deeper substrate just to keep the plants down! 5 or 6 inches is the max I have ever used.
Bear in mind too that in a healthly heavily planted tank, the roots themselves give off oxygen. Only when the substrate becomes root bound and overloaded with organics does it become a problem. With very mature tanks, 5, 8, 10 years old, a shallow substrate can become one big root ball.
|01-04-2004 04:37 AM|
Thanks all for the great and very interesting replies! I am going to go with the Eco-Complete. I finally found a store in the area that sells it. $22 for a 20lb bag~more than Dr. Smith but with no shipping ends up being a few bucks cheaper. Yeah for me! I think I will go with about 7 bags which will give me 140 lbs of substrate. I think that will give me a good 2-3in on the bottom of the tank. If not I will get some more. Thanks again guys for all your help. This is the best resource I have found for learning everything I need to know about planted tanks. Thanks
|01-04-2004 02:31 AM|
If the substrate is too deep, especially if you're using a small grained
subtrate, chances are you'll get some anerobic spots eventually.
I've personally had a nice stand of crypts just starting to wither away.
I pulled them out to find blackened roots tips on the ends of healthy roots.
Only use a deep substrate if large root systms are going to work their
way though it - otherwise
1) Its a waste of money
2) You may get anerobic spots
There's no apparent benfit to a substrate thats 4-5" deep, except
to the retailer you bought the substrate from.
I'm growing my foreground plants in 1" of flourite in the front - which
slopes to 3"in the back.
Take a look - notice - no substrate line in the front - 1" deep
|01-03-2004 10:53 PM|
Originally Posted by SCMurphy
I do understand arrogance.
Reef tanks: similiar bacteria, same processes.
Sean, here's where I stand: If there are anoxic/anaerobic areas, sans undue amounts of detritus, under shallow rooted plants, they aren't hurting anything. If there are anoxic/anaerobic areas near deep rooted plants, the oxygenation you want will occur... Unless you've got lots of buried organic material, you shouldn't see toxic effects from sulfur compounds. This is not a drastically different situation from the deep sand beds which have become the standard in reef tanks. A dead buried fish would cause problems in either case.
|01-03-2004 10:35 PM|
|SCMurphy||You win...enjoy your tanks...sorry you don't understand that we aren't talking about reef tanks.|
|01-03-2004 09:48 PM|
Sorry, rumours of *problems* from the release of toxic substances. I wasn't clear. In most cases I've read about where there actually is a real problem with sulfur (i.e. dead fish) it's related to large amounts of buried detritus, not the slow sifting of mulm from above.
Deep, denitrifiying substrates don't necessarily rely on "daily interplay." They generally rely on the products from aerobic reactions above making their way into anaerobic areas below. I believe that many reef aquaria, with very little photosynthesis, also maintain very low nitrates. Anaerobic respiration seems to "keep up" in those cases -- there's a lot of surface area for these bacteria.
Help as much as you want, but we don't "know" that deep substrates cause problems. I agree that unhealthy deep substrates can.
Also, I didn't disguise anything (I was arguing against your warning about deep substrates/shallow roots/whatever all along), and I didn't ask you to do anything for me.
Finally, I had to jump in following your "This is coming from an aquatic ecologist." hubris.
|01-03-2004 09:21 PM|
It sure doesn't seem excellent....
Remember that this is a forum for helping people avoid problems in their tanks. If you don't like being redirected to the answer of the question, there's nothing I can do for you. If you have a point and try to disguise it, don't be surprised if you don't get a reply that matches what you are thinking of. Personally I'd just like to reiterate that all I want is to help the person who asked a question avoid a potential problem that we know about.
Denitrification is accomplished by anaerobic processes, yes, but not fast enough to rid the aquarium of all nitrogen compounds, so you still get the slow release of ammonium and methane from other anaerobic processes.
But in a planted tank those aren't the problem. The creation of the nasty sulfur compounds that you started to bring up earlier also occurs in the anoxic substrate, these ARE poisonous. Rumors? No, not rumors, ask the last person who got to smell rotten eggs when they stirred up a substrate and pulled up wilting crypts with blackened root tips. What a wonderful result of a deep sand bed.
The daily interplay between aerobic and anaerobic processes in a planted tank substrate is absolutely necessary for the rooted plants to obtain their nutrients and detoxify the area around their roots. The problems occur when a substrate goes completely anoxic and is never “switched” allowing the “rumors” to build up.
|01-03-2004 08:39 PM|
Excellent condescention, thanks.
DO would be used by aerobic bacteria nitrifying/nitrafying the organics... Mostly nitrates being the result. Once the oxygen runs out, Anaerobic Nitrate Respiration then Anaerobic Denitrificaction (which I believe can occur via more than one pathway - one w/no sulfur) can reduce nitrate to gaseous N2.
My point is that there is a whole methodology of using Deep Sand Beds to detoxify aquariums, and I think the rumours of the release of toxic compounds are pretty exaggerated. That seems relevant.
|01-03-2004 08:07 PM|
Originally Posted by hypsophrys
Except that the DO would be used up before the water carried it down through 4 inches of gravel. Where as Mulm wouldn't be used up, and would just accumulate. Without any plant roots penetrating down through the gravel there wouldn't be any DO delivery that way either, which was the original problem I was trying to help someone avoid.
|01-03-2004 08:00 PM|
|hypsophrys||Well... I'd hypothesize that if mulm can go somewhere, so can water w/dissolved O.|
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