Airation

[Bad Inferno]

I have been thinking of putting my air stone on a timer and turning it on at times during the day for an oxygen recharge and on all night. (I have pressurised CO2 on a ph controller)

I like the look of no bubbles in my display tank, however can remmeber when I didn't have it going the discus got skittish after a while.

How long do you think the oxygen lasts in the water, ie could I have the airstone on for 1 hr and off for 3 hrs during the day, and on all night ?

rob

[duck]

I don't know how long the O2 would last,I suppose it would depend on how many plants you have,How many discus you have and big your tank is.
I would go for leaving on at night only see how you go,Like turn it on 1hour after light's out then off 1 hour before lights on.

I suprised that the discus a skittish,Do have any surface movement for gas exchange?that would help aswell during the day.

The longer you leave the airstone on the more CO2 you are going to use,As it gases out the CO2.

[Bad Inferno]

CO2 usage hasn't been a problem to date although I only run around 20-25 ppm co2, I use it more for ph stability. My fire extinguisher bottle has lasted 12 months.

My airpump is also airating my storage water so I'll get another pump and put it on a timer for the tank

[Skulljug]

Ok this is going to be a bit long - But I struggled with this myself and love the solution.

The problem with having the airstone on at night is that you are going to rapidly degas you c02 which will raise your ph (depending on your KH, but in discus tanks it tends to be pretty low) and when it stops in the morning you PH will swing downwards - I was trying to avoid this and also find a way to turn of my diy c02 at night.

What I came up with is that I have my co2 bubble into a trap in the tank (Like an upturned test vial), from there a venturi on a power head sucks it from the trap into the diffusor - Which is just a vertical piece of PVC, The water and gas are pushed in at the top and out through foam at the bottom. At night the power head turns off but turns back on for 1 minute every hour. at the same time an air pump comes on, pumping air into the trap and turns off at the same time as the power head. This means at night I am dissolving o2 into the water while not gassing of much c02. PH stays stable and oxygen is saturated during the night.

As for daytime, if your plants are growing well don't worry about it, they will be producing heaps of oxygen.