Cardinal Tetras Not Moving Much

[Alexp08]

I have 9 cardinals in a 20 gal high tank. I checked all the parameters and they are fine.
But my tetras are not moving much they either stick to the front of the tank or the front corner. I read somewhere that cardinals dont like alot of water movement so i slowed down the rate of my AC 30 to a little below half. This seemed to help.
However i dont think it will give me adequate filtration at that rate.
 
So could there be another reason they are not moving alot?
Or is it my filter and i need a different one, if so what are good options.  
 
pic of tank

 

[AshleyNZ]

Maybe try posting more info , like how long the tank has been established (Set up) for, the specific water parameters (Ammonia, Nitrite, Nitrate and pH) and what test kit you're using, 
What temp is the tank at? 
These questions can help people give you better answers as to why your fish are acting this way

 

[Byron]

I agree with Ashley.  But while we're waiting for the additional info, I would just mention that this is not an active swimming species.  I have had groups of cardinal tetra for as long as I've had fish.  They do not like water currents, but provided they can get out of direct current they will be fine.  But they remain together in the shoal, rarely breaking apart, and barely swimming most of the time.
 
The other thing I see in the photo is the light.  Cardinals have what has been termed a light phobia, which is actually common to most forest fish.  They are down close to the substrate for a good reason...they naturally live among fallen branches and overhanging marginal vegetation.  In some of their habitat where there are submersed plants, they remain among them.  I have found that floating plants that are significant in structure alleviate much of their natural shyness and uncertainty.  By significant floating plants I mean ones with some substance, such as Water Sprite, Frogbit, Water Lettuce, or some of the stem plants that grow nicely floating.  As opposed to duckweed, for example.
 
The other thing I see is the lack of upper fish, which I find will also boost their confidence.  I appreciate this may be a tank in the making, so once you have more fish you may see some change in the cardinals' behaviours, but don't expect much.  My current group of wild cardinals remained along the back wall of the tank for months, well over a year, behind the vertical leaves of a Ruffled Sword.  They came forward at feeding time, but otherwise they pretty much remained in the back.  For the past year or so, those that are left have been out and about more, though always in the lower half of the aquarium, and just cruising calmly, except when a pair initiated spawning behaviours.
 
Byron.

 

[Alexp08]

Well i guess my parameters are not fine. I just added 7 of the 9 cardinals 3 days ago, when i check them then they were fine. Anyways.
 
API test kit
Ammonia = .20ppm
Nitrite = 0ppm
Nitrate = 1.0 ppm
 
The tank has been running for about 6 months now. But had only two fish in it for about a month. Then in a week in jumped to 11
9 cardinals
2 GBR
 
My ph is reading 8
Which doesn't sound right at all, ive done nothing to alter the ph at all. I use tap water and the water from the tap is 7.0
 
These are suppose to be tank born and raised from a farm in Florida
 
temp is 82-84f

 

[fluttermoth]

Apart from your water quality (you're having problems there because you should never add more than 50% of the current stock at once) I think your main problem is lack of height in your decor.

Fish like to be near cover most of the time. You and I know there are no predators in your tank but, crucially, your fish don't, so they're not going to want to move too far away from a convenient hiding place.

If you get some tall or, as Bryon suggests, floating plants, you should find your fish more confident.

As for your pH; when testing your tap water, do you leave it to stand for 24 hours first? Many water companies temporarily alter pH and you need to let that 'wear off' before you test to get a true level.

It could also be your substrate. Put two jars of water, one with a handful of substrate and one without, one one side and test after a couple of days to see if they differ at all.

 

[Alexp08]

Yes i did just the gun on adding the fish. But i got a great deal and didn't have a spare tank at that time.

Im hoping the plants get some height soon.

I didnt know that avout letting the water sit for 24hours before testing. That is very interesting!

Also the substrate is seachems flourite

 

[Byron]

I would not worry about ammonia, nitrite or nitrate.  These are not (or should not be) any problem here.  You have sufficient plants to handle any new fish.  So we can set that issue aside.
 
To the pH...as fluttermoth said, tap water should be set out for 24 hours before testing pH.  It may also contain CO2, and this needs to out-gas, as it will affect pH readings.  You can out-gas CO2 by the 24 hour method, or you can briskly agitate some tap water in a covered jar for a few minutes before testing.  As far as I know, this agitation method works for both issues so it is quicker.  The result of the pH test should then be accurate.
 
Flourite substrate will affect water parameters a bit.  I used this in one tank, and found my pH rose marginally.  This seemed to lessen as the Flourite aged, and by the second year it wasn't noticeable.  You can use fluttermoth's suggestion to ascertain how much in your case.
 
Byron.