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Ideal Substrate for my 90gallon?

3K views 25 replies 9 participants last post by  Buck 
#1 ·
I am looking to set up a planted tank in my 90 gallon tank. I currently have just the cheap gravel. I want to upgrade to either flourite or perhaps eco-complete. Are there any endoresments or recomendations out there for either. I have noticed there seems to be some debate on which is better. Also the eco-complete comes in 20lb bags and the Flourite comes in I think a 17lb bag? How many bags would I need to get a deep enough layer for good root growth? Do most people mix with gravel or use is by itself? Thanks for the info. This is my first post but all the information on this forum has already been greatly beneficial to me.

Rasconza
 
#2 ·
I recently started up my 72g with 140#s of eco-complete. I must say that I have been very impressed with this product. As a matter of fact I have used laterite in a few tanks now and the eco complete seems to do a much better job. An extra bonus is that eco-complete comes with bacteria already in the bag-thereby cycling your tank that much faster. One other cool thing is that eco-complete has an ability to "settle" itself. By that I mean that there are different granule sizes in each bag. The larger granules stay on top while the finer granules shift to the bottom-which is much preferred by your plants sensitive roots. Im sure 180-200#s would be plenty for your 90g. As stated before I have 140#s and have about a 6-7in. rear depth with about 4-5in. of foreground depth.....yeah its expensive but worth it :)
 
#3 ·
Thanks for the reply Verminaard. The eco-complete does seem nice and it is considearbly cheaper than the flourite as well. You say you have anywhere between 4-7in depth of substrate? Is that much neccesary? I always thought recomended was around 3ish. One other question~the eco-complete looks very dark? How does it look in the tank? Black? Just curious on that one. Thanks

Rasconza
 
#4 ·
Yes I have about 4-5in . in the foreground and slightly deeper in the rear. I have a very heavily planted rear of the tank(ludwigia, cabomba, wisteria,rotala,lloydia,etc....)and feel that with the extra depth the root systems can go pretty deep and have a great supply of nutrients. I have had tanks with a 50/50 mix of laterite/gravel and only 3 in depth with varying success. Case in point-I have a 55g with this mix (the 50/50 and only 3 in deep)with a large patch of echinodorus tennelus dying off -I believe the reason is the plant has absorbed every last bit of nutrients from the substrate and it grew so thick that the roots are probably choking each other out......I would have been better off with a much deeper substrate. Im sure there are other sources of info on this forum elsewhere on ideal substrate depth........
 
#5 ·
Thanks for the info. I may go a bit deeper then. I did not realize that the plants would completely use up the nutrients from the substrate. I assumed over a long period of time the nutrients would become depleted. Good info tho. Not sure if you saw because I edited my last post. What do you think of the color of the eco-complete in your tank? Does it look good? Seems very dark in the bag. Thanks again.

Rasconza
 
#6 ·
I really like the dark look of the eco-comp. I have always read that a dark substrate is usually preferred by most fish. Check out my tank in the photo album section under 72g planted bowfront and you can see that the dark color of the substrate (with the black background) gives a very nice contrast to the colors of the plants. good luck with your tank :D
 
#8 ·
You won't need that much substrate, 3-4" is the maximum; I mean with 4" of substrate how much depth will be left for your fish?! The dark substrate is great for bringing out the best colors in your fish, and it's good that it won't reflect light off causing stress to your fish. If you can't find Eco-Complete locally, go to Drs.Foster&Smith...they have the best prices around including shipping...
 
#9 ·
Raul-7 said:
You won't need that much substrate, 3-4" is the maximum; I mean with 4" of substrate how much depth will be left for your fish?! The dark substrate is great for bringing out the best colors in your fish, and it's good that it won't reflect light off causing stress to your fish. If you can't find Eco-Complete locally, go to Drs.Foster&Smith...they have the best prices around including shipping...
He's setting up a 90 gallon tank so he should have plenty of room left for the plants and fish. Lots of people (think Amano) aquascape their tank with very radical changes in substrate depth, it gives an undulating (rolling hills) feel to the 'scape. Disclaimer: this is coming from a guy who has substrates that are less than 3 inches deep.

The only thing I would caution against is using a lot of shallow rooting plants over the deepest substrate. You want you deep rooters there so that the plants do what they do best and keep the substrate oxygenated. While I can demonstrate that plants can overcome an anoxic substrate, one that has decomposed to the point of being toxic is dangerous to your plants.

This is coming from an aquatic ecologist.
 
#10 ·
SCMurphy said:
While I can demonstrate that plants can overcome an anoxic substrate, one that has decomposed to the point of being toxic is dangerous to your plants.
Are you talking about sulfur compounds? I'm just thinking you'd need a lot of organic material there in the first place to create toxic levels of these. 3" of sand and laterite, for example, without any nitrogen or carbon compounds, wouldn't be an issue, even if it was densely packed with no roots, right?

Ian
 
#13 ·
hypsophrys said:
Well... I'd hypothesize that if mulm can go somewhere, so can water w/dissolved O.
:roll:

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.
 
#14 ·
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.

Ian
 
#15 ·
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.
 
#16 ·
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.

Best,
Ian
 
#17 ·
You win...enjoy your tanks...sorry you don't understand that we aren't talking about reef tanks.
 
#18 ·
SCMurphy said:
You win...enjoy your tanks....
How magnanimous.

sorry you don't understand
Oh, wait, I thought I won?

I do understand arrogance.

Edit:

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.
 
#19 ·
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 :D

 
#20 ·
Thanks all for the great and very interesting replies! :D 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

Rasconza
 
#21 ·
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.
 
#22 ·
rasconza said:
Thanks all for the great and very interesting replies! :D ......... This is the best resource I have found for learning everything I need to know about planted tanks. Thanks

Rasconza
Your welcome, don't forget to post some pictures of your tank when you get it rolling.
 
#25 ·
Raul-7 said:
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?
It's too new to know yet.
 
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