Oxygen

[miltiadis_s]

eyz.. how do you know when theres enough oxygen in your tank? i have an internal filter which runs 24-7 and an air pump that just runs for a few hours a day...

cue

 

[crazie.eddie]

If you see most/all of the fish at the surface gasping for air, then you need to add more O2.

 

[helterskelter]

You can get test kits that test the O2 in the water and as long as you over 7mg/l your perfect i believe (For most fish, very few need it higher)

The filter is best on 24 hours a day or the bacteria can die of low O2 levels as the lack or flow through the media.
As long as you stocking to stocking guide lines then their should be no reason to be worried, it's only a problem when over stocking.

Sings of low O2 are all fish gasping at the surface, bottom dweller's darting up gulping and dashing down again. Fish hanging around aeration bubbels and flows of water, as these are the best places to first get the disolved O2.

Helter

 

[The-Wolf]

you can buy O2 test kits but this is not really neccisary.
If you suspect that your tank is low in O2 then increase the surface aggitation
and also lower the temp by turning off your heater.
the lower the temp of water the more dissolved O2 it can hold.

some indications that you have low O2 are all the fish are at the surface
with rapid gill/mouth movements, and or the fish are jumping (especially in ponds)

 

[miltiadis_s]

thank you for the fast replies... are fish meant to open and close their mouths in the water all the time (stupid question lol)
cause mine are doing it all the time.

 

[helterskelter]

yes, at a slow steady rate, the take in the water and pass it over the gills to absorb in the oxygen.

If it's going quite fast then they are trying to pass more oxygen over the gills.

 

[miltiadis_s]

perfect thanks.. and if they go to the surface of the water and blow bubbles does that mean they are healthy?

 

[helterskelter]

Some fish normally blow bubbles, depends on the fish to be honest. What are u keeping and what it's doing?

 

[xing]

bottom dweller's darting up gulping and dashing down again.

don't cory's do this anyway?

 

[helterskelter]

From time to time yes they do, but you should notice when their doing this much more then the norm (like every 2-3 mins)

 

[leoslizards]

My dwarf gouramis do the fast dash thing. Normal right?
My guppies are aways at the top of the water. Normal right?
Only one time have I had all my fish including some shrimp at the top of the tank and that was when my power went out for a couple days and there was no surface agitation. All the fish survived and only two shrimp. The ones that stayed at the bottom of the tank died. Btw I never use an air pump because I have live plants. This is ok right?

 

[helterskelter]

My dwarf gouramis do the fast dash thing. Normal right?

All gouramis can breath atmospheric air, thay have a special labyrinth organ allows then to do this and is present in most Anobantoids.

My guppies are aways at the top of the water. Normal right?

Guppies are a surface water fish, so nothing wrong.

All the fish survived and only two shrimp. The ones that stayed at the bottom of the tank died.

Shame that you lost some fish and/or shrimp, but 2 days is a long power cut and if most survived you should be pleased. Perhaps think of adding aeration at night, but if ther's no current problems then you safe.

I never use an air pump because I have live plants. This is ok right?

Live plants add oxygen during the day, how ever at night they remove it, if u have a lot of plants then they could of dropped oxygen down to a dangerous level