Cycled gravel bottom or uncycled bare?

[Fishfanatic]

I plan on purchasing (6) 3-3.5" Discus next week and have a question. Should I grow them out in a fully cycled 70 gallon aquarium with a sand substrate or a bare bottom 55 gallon? I plan on regular water changes either way I go.

Is it correct to assume that everyone's BB tank is not cycled because of the lack of substrate? I know the beneficial bacteria live on the sponge filters, etc, but also thought the substrate provided more surface area for the bacteria to multiply.

Any advice would be greatly appreciated.

Oh and one last question. Does a 50% water change daily seem like a good starting point or should I just monitor the water parameters and decide how much to change then?

[kirkp]

I'm not an expert on this but my guess is that the majority of responses will recommend growing them out in a bare bottom tank.

As to a tank being cycled or not. The lack of substrate has nothing to do with a tank being cycled. It has to do with the development of a sufficient number of biological organisms to treat the waste generated by the fish. In a BB tank, this would be on the filter material such as a sponge filter or power filter. While there would be some of those organisms on the gravel surface, as long as the filter capacity is adequate for the tank, the gravel being gone will be of little consequence. This all assumes that you wouldn't be running a undergravel filter. In this case, the gravel acts as the filter and the oxygenated water passing through the gravel feeds the aerobic organisms which live on the gravel. It's late so I hope this makes sense.

For the water changes, maintaining clean water is what promotes the greatest growth of the fish. This would suggest that 100% daily water changes would be the best and there are probably some breeders out there that do this. If you could maintain a schedule of 50% daily that would be good. Or, 50% every other day. What you choose is up to you but remember, the more often the better.

Kirk

[1077]

I am not a fan of bare bottom tanks unless it was for breeding purposes. I see no beauty in a sterile glass box of water especially if it were sitting in the living room. I keep four discus in an 80 gal. with fine gravel, artificial plants along the back and sides, two clay pots that they frequently use , large driftwood, and ssome large smooth river rock. I change 25 percent of the water every four to five days and feed them a variety of foods twice a day. Two of the fish i have had for two years and two were recent additions. The tank also houses a pair of blue rams, neon tetras, gold white cloud minnows, a shoal of six julii corydoras, and one white spot pleco. Temp .84 degrees. Hope some of this helps you decide.:D

[Don Trinko]

I cant stand the appearance of BB so I have gravel in 2 tanks and sand in 2 others.
BB is less work and easy to see when it is dirty. With gravel you will need to make an effort to vacumn the sand several times a week. Don T.

[Fishfanatic]

Well thanks for all the feedback. Iv'e decided to go with a small layer of gravel on the bottom. I used some water, sponge filter and java fern from a previously cycled aquarium and everything seems to have leveled out after a slight ammonia and nitrite spike. It's been running for about a week with a couple small swordtails so I'll check everything again when the Discus come in next week. I'll post some pics when I get them...I'm so excited!!!!!!

[ShinShin]

Gravel is not recommended for discus tanks because gravel, especially accompanied with UGF filters, is a parasite heaven. Gravel without a UFG under it serves little purpose as a biological filter. UGF filters supply O2 to the nitrifying aerobic bacteria. Gravel with no UGF harbors anaerobic bacteria which provide no benificial biological filtration, and in some cases may harm a set-up.

It doesn't matter who says what about how to clean your gravel, you can't vacuum it enough to keep parasites out of it. That is why the professional keepers don't use it in any of their tanks. UGF's have been dubbed "discus killers" years ago, and with good reason. I've viewed thousands of discus in my years, and never has a discus kept in a gravel tank surpassed a bb tank discus in overall color, size, and health. I have tried it both ways. As long as I keep discus, I'll never have to buy gravel.

Mat

[1077]

Biological bacteria (the good kind) collects on everything in the tank. The filter, the decorations, the plants real, or artificial, wood, and on the substrate. Parasites are usually introduced to the aquarium through new fish and or live food. Not everyone who uses gravel or sand has parasites in their tanks.many fish harbor parasites in their bodies without any adverse effects much the same way humans do. And they are kept in check through their immune system much the way our immune system works. I do not believe the gravel works as a biological filter but rather it creates more surface area for that bacteria to colonize. I suspect there are more than a few people who care for discus that have gravel or sand substrates and healthy happy fish. I am pleased your fish do well without it but to say it is not recommended would in my view only hold true for those who breed them and as such, normally feed much more to many more fish to attain what some might view as abmormal growth. Water changes and proper maint will always produce healthier fish irregardless of substrate or lack thereof. IMHO:)

[kirkp]

Be careful with how many discus you add to the tank. Right now it is cycled with a biological capacity based on a few swordtails. When you add the discus you'll be significantly increasing the waste load that the filters are intended to handle. Depending on how many fish you add, you could end up with a significant ammonia/nitrite spike that could harm your fish. You'll have to keep an eye on things and may have to do daily water changes. This is one reason cycling your tank with ammonia instead of a few fish is recommended. The fishless route will get your filters to their full potential.

Kirk

[ShinShin]

While it may be true that nitrifying bacteria grow on everthing in the tank, more aerobic bacteria grow on surfaces that are rich in O2. The main purpose of a UGF plate it to pull O2 rich water across the gravel that the bacteria colonize. Too thin a layer or too thick a layer of gravel renders the filter less efficient. No UGF plate under the gravel allows only the surface layer of gravel to become colonized. Too deep a layer of gravel can cause a growth of anaerobic bacteria to become colonized and disturbance of this colony can cause foul water conditions up to and including toxic levels. The size of the gravel itself also makes the UGF more or less efficient. Sand, because of its tendency to pack tighter is worse than gravel when it is too deep.This is why a sponge is so efficient because of all the surface area which O2 rich water is passed through.

Parasitic pathogens occur in all tanks. They can be spread by water vapor from tank to tank, as well as spores in the air. Pathogens such as Ich are present in every tank of fish if the water is not too high of a temp to kill it. Ypu do not need to introduce a fish with Ich to get Ich, nor do you need a host to introduce a fungal attack.

The major drawback of UGF's is that they trap a layer of detritus (including food and fecal mater) under the plate. This detritus not only is a sanctuary for many pathogens, it also decays, adding unwanted organics to the water. It is many of these organics that we do not want in our growout tanks because excess organic waste in the water is a deterent to optimal growth.

Mat

[Fishfanatic]

I do have a 55 gal tank that has been setup with Angels for over a year. What if I moved the Angels to a new home and removed the gravel from the 55 gal tank? I thought about siphoning the water to barrels so as not to foul the water, removing the the gravel then siphoning the water back in. Would this cause my thank to recycle or should there be sufficient bacteria present in the water, filter and driftwood? I also plan on doing 50% daily water changes. Any suggestion? By the way, I plan on (6) 2-2.5" Discus.

[1077]

:( My apologies, I did not see any mention of UG filter in original posters question. I agree that UG filters trap much unwanted pollutants under the plate. I have two 29 gal. tanks with sand substrate. While most of the food what little isn't eaten, and poo remain on the surface sand indeed must be sifted regularly to keep pockets of pollutants and gases from forming.

[Don Trinko]

IMO BB is ugly. BB is less work to keep clean, IMO That is why breeders use BB.
While I have only had discus for 2 years now all my tanks have gravel or sand. My 1st 7 discus are still healthy and have grown from 2"+ to 5"+. No; I don't have the mythical 8" discus but I do have one well over 6".
Just my opinion; Don T.

[Apistomaster]

I don't like bare bottom tanks but the amount of sand, not gravel, i use is usually no more than 1/4" thick. This little sand does not greatly increase the amount of work to keep clean than a bare bottom.

In closed systems relying on bacterial nitrification, all surfaces contribute to the nitrification cycle. In large aquaculture systems as much as 30% of the nitrifying bacteria are on every surface expose to the water. Probably only about half that much occurs in an aquarium.

The need for an adequate biological filter is not diminished.