can you fill your water level of a tank all the way up?

[Rosemary]

If you have bettas, ADFs, or other animals that surface to take in air, be sure to allow room for them.

The Aquaclear will work fine with a higher water level. In fact I find that it works better with a higher level than a lower level.

 

[Galaxie]

I have 4 AC's and since they are HOB's, you can't fill to the point where they won't work. If you did fill that high, you'd have a steady stream of water flowing into your living room.....because HOB's hang on the top edge of the tank. This seems logical anyhow?

My pleco likes to come up for gulps of air occasionally. I understand this is how he manages to suspend himself in the strangest positions....upside down, etc. So I leave him about 1-inch.

My tank with heavy plants is filled right to the rim. No gas exchange, no evaporation.

One thing to keep in mind, some HOB's backflow a little if you shut off the power, so....if you fill to the rim then shut off the power, you might be overflowing.

 

[patoloco]

I'm currently thinking of reducing my tank level a little bit. I keep a clown knife fish and havestopped feeding him live guppies bacause he smacked his head against the reinforcement glasses while tying to catch one. I'll go around 1" below the tank top.

 

[mishi8]

As others have said, it's fine to fill it up to/past the filter outlet.

The only limitation I can see is with something like a heater. In my 10 gallon, I have a non-submersible heater, so I can only fill the water up to a maximum level on the heater, and given the way it mounts to the glass, it gets in the way of the hood if it sits too high. Thus my water line is well below the black trim on the tank. I'm considering buying a submersible heater so I can raise the water level.

 

[NDferro]

The basic idea is that you want space for the water returning from the fiter to splash and mix air in to water this is the primary method for air to dissolve in to the aquarium water air pumps are more for show

 

[gagaliya]

The basic idea is that you want space for the water returning from the fiter to splash and mix air in to water this is the primary method for air to dissolve in to the aquarium water air pumps are more for show

i thought most of the oxygenation process is done inside the hob power filter BEFORE the water hits the surface of the tank? Water splashing on the surface from hob is just an added bonus. Because both of my ac50 does not make any splash, it's just a very gentle stream going back to the tank.

personally not too worried about surface exchange though because i have 2x 24" bubble wands, the entire surface of my tank is full of bubbles from them

 

[mishi8]

The bubbles don't actually put air into the tank. Neither does the water going into the tank from the filter. It's the movement of water that helps break the surface tension and allows exchange of gases to oxygenate the water.

 

[gagaliya]

The bubbles don't actually put air into the tank. Neither does the water going into the tank from the filter. It's the movement of water that helps break the surface tension and allows exchange of gases to oxygenate the water.

yes i am aware of that, the bubblewands create tons bubbles which in turn create a lot of surface movement.

And the water moving through the hob should be fully oxygenated before it hits the surface? because well the water is MOVING through the hob.

 

[Slappy*McFish]

Gas exchange mostly takes place on the surface of the water in the tank. It doesn't have to 'splash' to accomplish this, it simply just needs to create water movement. The ripples/waves generated by the filter across the surface of the water is how this exchange takes place.

 

[mishi8]

yes i am aware of that, the bubblewands create tons bubbles which in turn create a lot of surface movement.

And the water moving through the hob should be fully oxygenated before it hits the surface? because well the water is MOVING through the hob.

I think I understand what you are saying. And I'm not sure if it quite works like that. Gas exchange would be a constant process, happening over the entire surface of the water, and not dependent on oxygenation that may take place within the filter. Is there enough gas exchange within the filter itself (as opposed to just at the site of where the outflow breaks the surface) to add to the total amount of oxygen in the tank? Is there enough surface area in an HOB to effectively add oxygen to the water?