Should you use an airstone and CO2 diffuser at the same time

[Box of Demons]

The seems to be a lot of different conflicting information out there on the internet I just bought myself a c02 unit and a regulator I also have quite a large airstone I've been told that I shouldn't use both together as the air stone will take the c02 to to the surface instantly is this correct do I need to set my CO2 on for around 5 hours a day but and then set a timer for the airstone afterwards.

Also can anybody give me any advice on how many bubbles per second I should be using for a Fluval 240 tank thank you and how many hours thank you.

 

[Byron]

The CO2 diffuser should be timed to be on only when the tank lighting is on. Light drives photosynthesis and the plants cannot use CO2 without the light. I believe some high-tech planted tank aquarists have the CO2 unit go off just before the light, say an hour, so the plants continue to use the CO2.

During night, it is important not to have CO2 being added as this will poison the fish. An air stone, or more accurately, increased surface disturbance, is important to ensure the CO2 is driven off.

From that it follows that during the day you do not want the CO2 being driven off. Provided always the CO2 is not beyond the need of the plants, as this too would harm the fish.

Others will have to advise on bubble speed; I do not use CO2 though I have looked into it (and decided against it).

 

[Colin_T]

Carbon Dioxide (CO2) is easily removed from water by aerating the water. If you are adding CO2 to help plants grown, then you should reduce or minimise surface turbulence when the lights are on. Basically turn off the airstones during the day.

Plants only use CO2 when there is sufficient light for them to photosynthesise.

At night when the lights go out, you should either turn off the CO2 or increase surface turbulence to get rid of the excess CO2 and stop the fish from suffocating.

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Carbon Dioxide is extremely acidic and will drop the pH of aquarium water in hours if there is insufficient carbonate hardness (KH) in the water. If there is not enough KH, the pH can fluctuate wildly between day and night and the fish can suffer from acidosis, which can kill them.

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Most people have the CO2 on a timer so it comes on when the tank lights come on, and it turns off an hour before the tank lights go out. This gives the plants time to use up the excess CO2 in the water before it gets dark.

 

[Box of Demons]

So as I am only on day one.. Does this sound right?

6 hours full daylight setting with c02 release.
C02 turns off after 5 hours leaving one hour for lights before lights go into nighttime mode.

As nighttime mode switches on leave airstone on for 8 hours?

Also just used my first in line diffuser (c02 art flux) it has left a scum flim on the surface is this safe? The flow from the roma 240 seems pretty weak.

Ty all for answering.

 

[Box of Demons]

Is this normal.. Day 2 added some beneficial bacteria.. No fish added c02 water flow seems weak and there is now scummy white stuff on surface.

 

[seangee]

As nighttime mode switches on leave airstone on for 8 hours?

By nighttime mode do you mean reduced lighting? Fish and plants both need a period of complete darkness.

 

[Box of Demons]

The fluval aqua sky 2.0 goes into a very dark blue hardly on at all.

 

[Essjay]

It still needs to be off for a period. Fish need a few hours of total darkness.

 

[Box of Demons]

So are ty etime right?

5 hours bright light and c02
1 hour bright light no c0w
Then 8 hours with air stone and no lights on?

 

[Colin_T]

You should have the air stone bubbling away when the lights are not on. If the lights are on for 5 hours with CO2 and 1 hour without CO2 (a total of 6 hours), the airstone should be on for 18 hours while the lights are off.​

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Unless you have Metal halide lights or very bright LEDs, 5 hours of light may not be enough for the plants.

Most aquarium plants like a bit of light and if you only have the light on for a couple of hours a day, they struggle. If the light doesn't have a high enough wattage they also struggle. Try having the tank lights on for 10-12 hours a day.

If you get lots of green algae then reduce the light by an hour a day and monitor the algae over the next 2 weeks.
If you don't get any green algae on the glass then increase the lighting period by an hour and monitor it.
If you get a small amount of algae then the lighting time is about right.

Some plants will close their leaves up when they have had sufficient light. Ambulia, Hygrophilas and a few others close their top set of leaves first, then the next set and so on down the stem. When you see this happening, wait an hour after the leaves have closed up against the stem and then turn lights off.

 

[Box of Demons]

You should have the air stone bubbling away when the lights are not on. If the lights are on for 5 hours with CO2 and 1 hour without CO2 (a total of 6 hours), the airstone should be on for 18 hours while the lights are off.

--------------------
Unless you have Metal halide lights or very bright LEDs, 5 hours of light may not be enough for the plants.

Most aquarium plants like a bit of light and if you only have the light on for a couple of hours a day, they struggle. If the light doesn't have a high enough wattage they also struggle. Try having the tank lights on for 10-12 hours a day.

If you get lots of green algae then reduce the light by an hour a day and monitor the algae over the next 2 weeks.
If you don't get any green algae on the glass then increase the lighting period by an hour and monitor it.
If you get a small amount of algae then the lighting time is about right.

Some plants will close their leaves up when they have had sufficient light. Ambulia, Hygrophilas and a few others close their top set of leaves first, then the next set and so on down the stem. When you see this happening, wait an hour after the leaves have closed up against the stem and then turn lights off.

thank you for the advice it's very appreciated there is so much conflicting information out there it's really difficult to know who to turn to. the book I have bought about setting up an aquarium says for the first week or so I should limit the lights to around 5 to 6 hours with CO2 I've only just put in some active bacteria and are doing this for 3 days I am still on day 1 so not in a rush do you advise I go up to 10 hours straight away even though the tank is only a day old?

 

[Colin_T]

It depends on how many plants are in the tank, what lights you have, and the height of the tank.

If you have lots of plants then try having the light on for 8-10 hours a day and monitor the algae levels.

If you don't have many plants, try 6 hours of light and monitor the algae levels.

Some plants will close their leaves up when they have had sufficient light. Ambulia, Hygrophilas and a few others close their top set of leaves first, then the next set and so on down the stem. When you see this happening, wait an hour after the leaves have closed up against the stem and then turn lights off.

Get some Ambulia or Hygrophila polysperma and monitor the leaves on them. They are a good guide to how long you should leave the lights on for.