Bare Bottom Tanks

[cupofjoel]

This is a simple discussion and an opportunity for me to learn. What are your thoughts on bare bottom tanks?

Pros:
-Don't have to clean the gravel
-No ammonia spike when gravel is disturbed
-Only need to focus on water changes
-Others?

Cons:
-No beneficial bacteria to grow on gravel
-Aesthetics (preferences of course if that is what you're going for)
-others?

 

[Fishguy13]

I am planning to do a bare bottom tank for a grow out once I set it up

 

[SRbettas]

Depends on the species your keeping some need substrate. Some dont need it at all like goldfish and in breeding set ups. I think it us up to the fish keeper to decide what's best for the tank. Oh and another con to substrate is any diseases that would require you to sanitize the tank.

 

[Byron]

A tank with no substrate is a very bad idea. The substrate is the most important factor in a healthy biological system. It is (or needs to be) the home of many species of bacteria, far more than live in any filter. The bacteria colonize the grains of the substrate; you can do without a filter (and should be able to) but not the substrate. That's the biological need.

Fish also need a substrate. Fish will be stressed over bare glass bottom. It is obviously not natural, and fish have evolved colouration so they can partially blend in with a darker substrate. Glass reflects light, and this can seriously stress out fish. Another aspect is that fish that spend tie on the substrate such as cories are in more danger of bacterial infections with a bare glass tank floor because there is no place for the organics to bury into so the bacteria can handle them.

Obviously the substrate providing the necessary bed for the bacteria will reduce if not eliminate the likelihood of disease. And parts of the substrate should never be touched because anaerobic areas are essential to a balanced system.

 

[Retired Viking]

I only use a bare bottom tank for my RES Turtles which get a weekly 90% plus water change.

 

[Colin_T]

You shouldn't get ammonia spikes form gravel cleaning the substrate. If you do, then you are doing something wrong.

All fish need a substrate on the bottom and a surface so they can orient themselves in the water. I have seen fish kept in bare glass tanks and they end up swimming upside down because they have no idea where the bottom is.

As Byron mentioned, fish stress when they can see a reflection on the bottom of the tank. If the fish are territorial, they will think there is another fish under them and try to attack/ fight it.

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If you have concerns about the gravel releasing stuff into the water when cleaning the tank, only have a thin layer of substrate. 1/4 to 1/2 an inch of sand or gravel is all you need for a fish tank. You only need enough to cover the glass bottom so the fish can't see the glass. If you want plants then have more substrate or grow the plants in pots.

 

[cupofjoel]

A tank with no substrate is a very bad idea. The substrate is the most important factor in a healthy biological system. It is (or needs to be) the home of many species of bacteria, far more than live in any filter. The bacteria colonize the grains of the substrate; you can do without a filter (and should be able to) but not the substrate. That's the biological need.

Fish also need a substrate. Fish will be stressed over bare glass bottom. It is obviously not natural, and fish have evolved colouration so they can partially blend in with a darker substrate. Glass reflects light, and this can seriously stress out fish. Another aspect is that fish that spend tie on the substrate such as cories are in more danger of bacterial infections with a bare glass tank floor because there is no place for the organics to bury into so the bacteria can handle them.

Obviously the substrate providing the necessary bed for the bacteria will reduce if not eliminate the likelihood of disease. And parts of the substrate should never be touched because anaerobic areas are essential to a balanced system.

When I clean the gravel, how far down do I go with the siphon? Just above the gravel and pick up deteritus near the surface or go further down to almost where I hit the bottom of my tank?

I can varying amounts of organic matter depending how shallow or deep I clean the gravel.

 

[Byron]

When I clean the gravel, how far down do I go with the siphon? Just above the gravel and pick up deteritus near the surface or go further down to almost where I hit the bottom of my tank?

I can varying amounts of organic matter depending how shallow or deep I clean the gravel.

If there are no plants, meaning it is open area substrate, you can go as deep as possible. I never do this under any solid decor (wood, rock, etc) as those anaerobic zones are there for a reason and should not be disturbed. In my 40g with sand and my cories, I never touch the substrate at all in any manner. They do the job in the open areas with their filter feeding.

 

[Fishguy13]

Would it be alright if I did a bare bottom for a fry raising tank and put some black paper under there so they can tell it is the bottom?

 

[Byron]

Would it be alright if I did a bare bottom for a fry raising tank and put some black paper under there so they can tell it is the bottom?

I know the reason given by those who advise no substrate for fry tanks, but as I think I explained previously, this is false thinking. Without a substrate, the accumulation of organics cannot be effectively broken down by bacteria, and that means the bare bottom is now much more "dirty" biologically than it would be with sand. And black paper on the outside does not stop reflections.