# settin up a gravelless tank



## drbenjamin (Nov 22, 2013)

*setting up a gravelless tank*

Hi All
I'm setting up my first aquarium and appreciate any advice you can offer. I've decided to start without any gravel in the tank. I have read several threads on this approach, and appreciate all the benefits to gravel and recognize that I may well switch over in the future, but for now I want to try leaving gravel out. 
Stonecutting is one of my hobbies so I have plenty of agates, opals and other decorative stone to use, and I will put in several plants in small glasses as well as a piece of driftwood. The tank will be a 40 gallon breeder and I have an Eheim 2217 canister filter. 
My main question pertains to biofiltration; will the canister media be sufficient for the nitrogen cycle or does the absence of gravel mean I should add a wet/dry filter as well? 
A second question is aeration; I've learned that gas exchange at the surface is the major route of aeration, but if I can avoid would prefer not to have a recirculating pump inside the tank. I have seen "skimmer" devices used as the intake for a canister filter (e.g Amazon.com: TOM Aquarium Surface Skimmer-canister and power filters: Pet Supplies) Will these help? Do I need to supplement aeration at all?

Thanks for all the advice, this forum has already been enormously helpful to me without my even posting any questions!


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## coralbandit (Jul 29, 2012)

The canister will be fine with no gravel in the tank IMO.I have too many breeding/fry tanks that have no substrate and only air driven sponges for filter.They are all fine and functioning biologically.
I have used the surface extraction before and they work well.Ehiem makes one also(a little higher quality a little more $).You should be able to get ample surface movement with just the return from canister.Are you using a spray bar?They can move large portions of surface.
Most don't experience oxygen issues so supplementing is not usaully necessary(mostly for gold fish).By keeping an eye your pH you can kind of tell if you're outgassing enough of the co2(pH will be lower if co2 remains present over time).Nobody needs a wet dry filter ,but they are excellent.I'm all sumps on my display tanks and love them.


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## majerah1 (Oct 29, 2010)

That all depends on the size of the tank you are setting up. A good deal of the BB does settle in the gravel no doubt but there are many who go bare-bottomed. My concern is the stone you will be using, and if it will raise/ lower your PH too much and if it is safe for fish. You will need to do a few tests on them to be sure. 

One will be a PH test. You will need to place a few drops of the PH regent on the stones, and see if it changes. The next is vinegar. Place a few drops in the rock, and if it sizzles, do not use it. 

To be honest, a canister is kinda a very large recirculation pump. The Eheims come with a spray bar and if you aim it towards the surface you can get some good aeration, without having too much noise going. What types of fish do you plan to keep?


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## drbenjamin (Nov 22, 2013)

*Re: setting up a gravelless tank*

Thanks for the replies guys! I appreciate the advice on stone selection - the ones I plan to use are all silicon based, shouldn't be any carbonates in there but I'll check them just the same. 
I'm a biochemist, I'm just learning about aquariums but am comfortable w/ chemistry and have my own pH meter so I'll stay on top of water measurements. On that topic, I was wondering whether people add any sort of buffer (e.g phosphate) to stabilize the pH in the tank? Or do you get enough buffereing capacity from the various organics that accumulate?
Regarding the spray bar, I have ordered the filter but it hasn't arrived yet so I wasn't aware of the spray bar. When I set it all up I'll look at the surface, souds like I may have sufficient agitation as it is.


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## coralbandit (Jul 29, 2012)

Excess phosphates usaully generate algae(boo hiss).Most just slowly acclimate their fish to the pH they have and thus have a much easier time with waterchanges.
Here's a link to drip acclimating,the best way to add fish.
http://www.aquariumforum.com/f2/drip-acclimating-fish-11327.html


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## majerah1 (Oct 29, 2010)

Agree with Tom there. I dont touch my PH I drip my fish to be sure they acclimate well enough to handle it.


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## jrman83 (Jul 9, 2010)

If you get a kh test kit and test your water you can determine whether or not it will have sufficient buffering capacity to keep your ph stable.


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## henningc (Apr 17, 2013)

I have over 20 tanks ranging from 20L-40 Brooders and only one has gravel. I use a sponge filter rated for 80-100gal in each tank. I used a magnum 250 HOT canister in my 175gal vat this summer and it provided enough filtration and oxygenation. Even on very hot days there did not seem to be any problems. In my bare bottom tanks I use java moss and when I have used other plants I simply put them in a flower pot and rest it on the bottom. Bare bottom tanks make water changes more effective and way easier.


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