Switching from aerator to co2

[CaptnDan]

No the Koi came in at the same time the Chichlids did. I did this to make sure there was no shock to the tank as you are elluding to.

Is this the same tank you cycled with 12 guppies, 2 of which survived? So the two guppies were in there when the cycle finished, then you added the Koi, the Cichlids, and the Pleco all at once? I'm not alluding to that shocking the system, I'm coming right out and saying it. And you are seeing the results now.

I know that the air stones only help stir the water and thats why I don't understand the fish reaction to my turning off the air.

The airstones are helping by effectively increasing the surface area of the tank. When the surface is rippled, the increased water to air interface area can exchange more gasses. Let the surface go calm and there isn't enough area for the exchange to happen fast enough. The fish get starved for oxygen and come to the top. After a while of this, they will come to the top and float belly-up. They are suffocating.

knowing that it was going to require more changes and filtration hence the oversized filter and cleaning it every other week.

So you have added another filter other than the Fluval-3 you had in there? That filter would be adequate if the tank was stocked normally, but Koi change everything.

Everybody that has answered this post, and the others has told you the same thing... Maybe there's something to it? I'll be amazed if 50% of these fish make it until Thanksgiving. You really need to do something....

 

[cmslick3]

So I admitt that I messed up with dumping sooo many fish in at once, BUT I added some real bacteria and I used to have massive ammonia and Nitrite. Both of those have settled now and the only thing I am left with is the excessive nitrate which I know Is not good for the fish. Hence why I asked if doing the CO2 injection would help the plants keep up their end of the deal. There is no place else for the Koi to go except into the toilet, but that ain't going to happen. Obviously this means I need to change more water more often over the winter but then it's smooth sailing again.

I guess I've had enough badgering about the stocking...

Thanks!!

 

[Star_Rider]

he states he does 50% wc every two weeks.

I suspect the nitrates are off because you wait two weeks to do this.

I don't agree with trying to get nitrates to 20, first determine what the nitrates from your source water is like.

adding plants will throw the nitrate count off. so get used to doing regular water changes weekly 50% per week is fine if your doing it every other week just bump it to once per week.

as you have heard, you are over stocked. but personally, if you do weekly changes of 50% this wil ease some of the stress on the fish. I do suggest you try and find a tank of craigslist and move the koi to that tank. koi will be fine with no heater and a filter as long as you keep your house heated 'normal'. the cichlids and the pleco are tropical..is this a 'common pleco'? if it is not one of the 'smaller' species..you will have issues with this fish in a 20.

as for planted tank..it'll help some of the ammonia, nitrite and nitrates however, there is more to be aware of in a planted tank..lighting will help determine if you need CO2 as well as species of plants.
anacharis usually needs descent light you'd need about 40 watts for this tank. and in the right spectrum. adding CO2 without proper lighting is basically a waste. what is your substrate?

 

[sumthin fishy]

I just wanted to point out, that water can be rich in both C02 and Oxygen. One does not replace the other. You can run both.

Airstones do not add Oxygen to your water. It is a myth. But its not complete information. The little bubles do not gass off o2 in the water. However, surface agitation does. The bubbles breaking the surface do indeed add oxygen in this manner.

 

[neonmadness]

You don need co2, my guess is those are tropical plants and are dying in the coldwater, raise temp and they should be fine