Over doing filtration?

[blue diamond Pete]

I recently changed from a community setup with an undergravel/2 powerhead setup plus a canister. Not wanting to use UG with future discus, I purchased another Aquaclear CF1000 and thought two of these would be plenty on my 90x40x50cm tank. While cycling the new filter with clown loaches and silver shark (from the past setup) they would be rapid beathing sometimes at the surface. I kept check of ammonia 0, nitrite 0, low nitrate, pH 7, temp 28deg so all ok. With a 30% water change fish were fine only to be gasping an hour later so more water changes. I hooked up the old powerhead to a sponge and opened the venturi to blow bubbles. This solved the problem and all is ok fish are happy.
Question 1 is why dont I have enough oxygen in the tank without the air bubbles?
The canister filters outlets were diffused with a funnel like attachment that came with the filters as I did not want strong currents and there was not a lot of surface agitation.
Now I did not want to have the power head doing nothing but blowing air so I put a large bio sponge on the inlet and a smaller one on the outlet to diffuse flow.
Introduced 3 small red turqs yesterday and are great, settled in and eating. Water tests fine.
Question 2 have I got too much filtration? Water changes will be 2/week.
Sorry for the long post but I needed to explain everything. Thanks, Pete

[Nathan]

Question 1 is why dont I have enough oxygen in the tank without the air bubbles?


because there is nothing creating oxygen in your tank, eg no airstone, no water agitation no plants pearling, so that why there wasnt enough oxygen.

also the higher the water temp the less oxygen there is in the water. so with your temp being 28 that would also reduce the oxygen, your best bet is to continue to run the air bubbler.


Question 2 have I got too much filtration?

you cant really have to much filtration as long as it isnt causing a lot of current. you definitely don t have to much filtration, if anything not enough

id keep the filters the way you have them (get rid of the ug though).

[AQUAMX]

Hi guys

I totaly agree with Nathan. I also think due to the filter setup aswell people can be restricted. Contact time with media etc in a cannister can affect all these things.

A trick i picked up to oxygenate the water using the equipment you have is to simply raise the spray bar,even if only at one end above the water surface to create aggitation. This will provide extra oxygen along with greater surface agitation.

Alternately you can fit a small air line into the begining of the spray bar or into the hose before it hits the spray bar to draw air and thus create the same affect as a powerhead.

Cheers

[taksan]

Question 1 is why dont I have enough oxygen in the tank without the air bubbles?
The canister filters outlets were diffused with a funnel like attachment that came with the filters as I did not want strong currents and there was not a lot of surface agitation.

Question 2 have I got too much filtration?
Pete

Question #1 you answered yourself ....
Question #2 is simple .... you can never have too much filtration

[blue diamond Pete]

Update
Now two weeks on and all is great.
The bubbles from the air inlet on the powerhead diffussed with a small sponge is doing the trick. I added a blue diamond and a pearl pigeon. The fish are happy and chemical levels are good.
Thanks for your help, Peter

[Merrilyn]

Great news Peter. Glad to hear all is going well.

[iro11a]

Hey pete i have the same problem as you yesterday i took out my internal powerhead and got a canister filter set up and water flow is really good and i moved the head so it wont give a big current but now i got no oxygen in my tank,but i dont wanna put the powerhead back in there with the air i thought a air pump with a air stone would be better because takes up less room

[blue diamond Pete]

Hi iro11a
The airstone will do the trick and help with agitation/oxygenation as I read it here somewhere and these people know their stuff. I believe that most of the oygen enters the water from the agitation at the surface and not from the bubbles in the water. Be sure to get a quiet pump because the constant sound/vibration can be annoying. I used the powerhead/venturi method with large biosponges to help with filtration as well plus I already had them. But if I needed an airstone to keep my fish happy I would have one of then also.
Good luck, Pete

[iro11a]

Yeah i brought a air pump today on the pack said its quiet but far from it my fish tank is in my room so i plan just to turn it off when i go to bed only problem with the canister filter and the air stone is the discus only stay at one end of the tank they will only hang at the inlet and not the outlet pipes i tried turning it different angles but dont seem to work?anyone got any sujestions?

[FishLover]

Aim the outlet so it can create surface movement in the tank. You don't need the air pump then.

Simple and effective.