How Many Bubbles?

[Ansel_Tk1]

Hi All - would love to hear your thoughts...

I am running a 65G freshwater planted tank. I have flourite as the substrate, CO2 injected before the intake at the canister filter.

My question is - How many bubbles/sec should I try for in the bubble counter? I'm not sure of the whole CO2 level thing. I have one of those CO2/mg/l from pH and KH charts. But my KH is so low that I don't think I am reading it right. I guess this begs the question - what are 'average' KH readings?

My ph is a constant 7 and KH stays around 1 or 2 dH.

I have a couple plants in there right now but nothing large (and there are only 3 of them, about 2 weeks in the tank, after 4 weeks of cycling). My intention is to grow as lush a green planted tank as I can. I also have 7 neons, 2 diamonds, 3 male guppies and 3 black mollies in the tank (in since the plants).

Thanks!

 

[Spinal]

Quick question, do you have an airstone in the tank? If so, thats probably your problem. If not, how does your filter return water to the tank? Is the spraybar submerged? If not (i.e. its above the water) thats your problem again. Simply put, with CO2, you want as little (preferrably none) surface agitation as possible.

And on a 260l, I've found 3/4 bubbles per second (roughly) to be more than plenty.

Michele

 

[Fillet 'O' Fish]

I have a 450 litre planted tank and I find that 2 per second gives me about the right balance of Co2

 

[Ansel_Tk1]

Hi - thank you. Actually - yes the spray bar is above the water surface. Is this a huge issue? How do you get O2 into the water if not?

Do you suggest the airstone for the CO2 or for getting O2 into the tank?

Thanks!

 

[ulster exile]

First of all, I'm no expert as I'm just learning all this stuff myself, but your posts have raised a few questions, so....

Is it really accurate to try and judge your CO2 output into the tank by talking about bubbles per sec? I mean, surely you should be trying to take an accurate measurement of the CO2 in terms of your PH and KH, which will vary for each tank.

Lastly, with a KH of 1 or 2 degrees, aren't you risking a PH crash as you don't have much of a buffer when the CO2 causes your PH to swing during the day....?

 

[BINKSY]

Hi

First of all you need to lower the spray bar to under the water level, also do not use an airstone when injecting co2 during the day, as the co2 will dissolve to quickly and have almost no effect.

 

[Spinal]

I thought of a great analogy. Think of your tank as a coke bottle. Its not airtight as you can guess.

Having a spray bar above the tank or an airstone will "shake your cola". You will lose the CO2 you have dissolved into your cola.

Regarding hardness, yes if your tank has very soft water, you can have isues with Ph crashes, BUT as long as you don't flood your tank with CO2 you should be able to maintain the acidity fairly constant. Another good idea is to shove some coral sand/gravel into your filter... works wonders...

Michele

 

[Ansel_Tk1]

Thank you all for your help.

I am going to move my spray bar then to below the water line.

I guess I will deal with the softness somehow with the coral sand or maybe baking soda (?)

Will moving the spray bar below the water line decrease the amount of O2 in the tank though? Do I need to get an airstone now if I do this?

Thanks for all your advise!

 

[planter]

With the lights on your plants are providing all the o2 your fish should require (unless your heavily stocked)
With your lights off your plants are using o2 and producing Co2. In a heavily planted tank with lots of fish it may be necessary to use an airstone at night. This will provided o2 and will vent off excess Co2 (produced by plants at night) and prevent the ph from falling too low in the night. A ph swing is to be expected in your planted aquarium so very low levels of KH could be the cause of ph crash. Bi carb will raise the KH. As for BPS start at one per second and adjust accordingly later.

 

[BINKSY]

moving the spray bar down under the water level will increase the co2 in the water, and as above you dont need an air stone during the day when using co2

Gordon