# Still struggling with CO2



## ojustaboo (11 Aug 2011)

Hi guys.

Have replaced my home made reactor with an up atomizer but still seem to be struggling to get a decent amount of CO2 into my tank.

I took a PH reading at just before 2pm before CO2 was on.  it was 7.2

After 2 hrs with about 3 bubbles  a second I took another PH reading, this time it was 7.0

I doubled the bubble to around 6 a second and took another count 1 hr later  (5pm) , it was 6.8.  

I opened the needle valve a fraction more, until a small stream of bubbles came out and an hour later (6pm) it was still 6.8.

I've just checked at 7pm and it's gone down to 6.6 (just, more like between 6.6 and 6.8    ).

The fish all seem perfectly happy, I'm concerned that my CO2 will not last long at this speed?

As the videos below show, I'm getting a mist in the tank (but I was when it was just 3 bubbles a sec).
Edit: put it on Youtube, slightly better quality



edit: video doesn't show it that well, here's a pic







I also have a video showing the bubble counter.

http://img810.imageshack.us/img810/9273/ddq.mp4

Finally, here's a pic of what my up atomizer looks like, should it look like this? sort of misted up?






Many thanks

Joe


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## Matt Warner (11 Aug 2011)

Hi Joe. Do you have the diffuser in the outlet hose or the inlet hose. By the looks of your photo it is in the inlet hose. If it is in the outlet hose then it seems to be the wrong way round. I always thought that you put them in the outlet hose. I could be wrong though!


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## ojustaboo (11 Aug 2011)

Have it on the outlet.

If you see this pic, the right hand side is looking at it as per my filter pic in my original post, the left hand side is  looking at it from the other side and you can see the up arrow is on the right hand side, which is the left hand side when it's round the other way,


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## ojustaboo (11 Aug 2011)

After another hr (8pm) ph is exactly 6.6


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## Matt Warner (11 Aug 2011)

Is your co2 system a pressurised system? Someone told me only the other day that these inline diffusers only work at a certain working pressure because the bubbles which get diffused are too big which might explain why you are having to inject so much, because the bubbles aren't dissolving properly.


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## Alastair (11 Aug 2011)

What colour is your drop checker though through out the day? I also noticed your spray bar isn't straight. Any reason for this? Some of the co2 would rise straight up where the bar dips down..


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## ojustaboo (11 Aug 2011)

Matty1983 said:
			
		

> Is your co2 system a pressurised system? Someone told me only the other day that these inline diffusers only work at a certain working pressure because the bubbles which get diffused are too big which might explain why you are having to inject so much, because the bubbles aren't dissolving properly.




Yep pressurised, 8 bar 1 side, 2 bar going into the atomizer


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## ojustaboo (11 Aug 2011)

Alastair said:
			
		

> What colour is your drop checker though through out the day? I also noticed your spray bar isn't straight. Any reason for this? Some of the co2 would rise straight up where the bar dips down..




It's finally starting to change, it's still not what I'd call lime green though.

Been experimenting with flow in the past couple of days, will put the bar back straight


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## Alastair (11 Aug 2011)

There's definitely more than enough bubbles By looking at that video. Pop your co2 on 2 hours before, then about an hour or two after lights on it should be a nice light green/lime colour. Are you using 4dkh water with bromo solution?


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## ojustaboo (11 Aug 2011)

Sorry, had to rush out as I typed last post, so typed it very quickly.

As it's a corner tank, it's very deep.  I've got a coralia pump in the corner pointing slightly down as per advice on this forum (similar to Ians lounge tank viewtopic.php?f=35&t=15058&hilit=Ian%E2%80%99s+Lounge+tank    , in the 2nd lot of pics about 8 posts down, the top pic shows the pump pointing down at the top right hand side ).  

I wanted to put my spraybar a couple of inches under the water, but the shepherds crook type ehiem thingy only lets it go about 1cm beneath.  I had the spraybar at an angle so as the bubbles at the lowest section were hopefully being pushed down by the coraila pump.  I also have floating plants, which means I cant have the pump right near the top, else the plants get sucked onto it.

Have now put the spray bar back straight


Currently the CO2 comes on at 2pm and the lights come on at 4pm.  CO2 goes off at 10pm and lights at 11pm.

PH readings in above posts were simply by putting tank water into test tube and testing.

Drop checker has 4dkh as brought from one of this sites sponsors.

Just this second  done another check  (9pm)  which is 3 hrs after I increased the bubble flow to what you see  in the video.  The PH has now dropped further to 6.4 and the drop checker is also now lime green.

I will also do another check at 10pm just as the CO2 goes off to see if it's gone down further.  It looks like I might be there at last.  Will repeat these checks from 2pm tomorrow, to make sure it doesn't keep dropping still further.  

But am I using much more CO2 than I should be with the bubbles moving that fast?

many thanks for all your help

Joe


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## Alastair (11 Aug 2011)

All tanks are different, but 6 bubbles a second does seem high especially with the up atomiser. I've heard people use less with them. I'm currently running 7 bubbles a second and that's on a 5 foot tank with glass diffusers. I'd leave it as it is set now, then clock at what time it turns lime green tomorrow, it's just a matter of being patient. With you turning it up only 3 hours ago, it could mean that the amount of co2 mid way through the day tomorrow could be much higher as you'll be having that higher rate from when it's first turned on. You may find you might need to nock it down a wee bit


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## ojustaboo (11 Aug 2011)

Thanks, just done final check at 10pm, it's still 6.4 but if I hold the test tube up against the one I did an hour ago, you can see it's slightly more green than 1 hr ago.

Will keep a close eye on it tomorrow


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## ojustaboo (12 Aug 2011)

I THINK everything is now fine.

Most of the fish are swimming happily all  over the tank, 3 however have spent the last hour or so at the top towards the back corner (triangle tank), but whether that's a fluke or they think there's too much CO2, I'm not 100% sure.

Have taken PH readings throughout the day.

2pm (2 hrs before lights on) 7.2
3pm - 7.0
4pm - 6.8
5pm - 6.4
6pm - 6.4
7pm - 6.4
9pm - 6.4

The reading I've just taken is definitely 6,4 according to my API PH test kit, it matches the colour card perfectly, there isn't the slightest hint of yellow.

I'm finding the drop checker a little hard to read (don't think the background fixed on the glass helps at all).  It's obviously blue when the co2 is off, now I'm not sure whether it's green or yellow, it looks more clear to me.  But nearly all of the fish are happily swimming in all areas of the tank, so I'm not sure whether I should be concerned or not.

CO2 goes off in an hour.

best

Joe


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## Alastair (12 Aug 2011)

A White ruler becomes useful for glass drop checkers I find, you can just pop it behind to get a better indication of the colour. 
Maybe just keep an eye on the 3 fish that are near the surface, if they weren't doing it before maybe the co2 is just a little bit high, do they do it all day or just as the day goes on?


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## ceg4048 (13 Aug 2011)

ojustaboo said:
			
		

> I THINK everything is now fine.
> 
> Most of the fish are swimming happily all  over the tank, 3 however have spent the last hour or so at the top towards the back corner (triangle tank), but whether that's a fluke or they think there's too much CO2, I'm not 100% sure.
> 
> ...


Hi,
Ideally, the tank should reach pH  6.4 at 3 PM and stay there. This isn't always possible, but thats the goal. From a plants perspective there is no point having maximum CO2 at the end of the day. It's a Catch-22 unfortunately, because you need a high injection rate to drive the ph down so quickly, but that rate left unchecked risks toxicity. That's why distribution is so important, because it maximizes the usefullness of the gas concentration that you do have.

Cheers,


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## ojustaboo (15 Aug 2011)

Many many thanks everyone

Think I'm finally there at last


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## Charlieh (16 Aug 2011)

> ojustaboo wrote:
> I'm finding the drop checker a little hard to read (don't think the background fixed on the glass helps at all). It's obviously blue when the co2 is off, now I'm not sure whether it's green or yellow, it looks more clear to me.



If you don't mind changing your drop checker permanently a good way to provide a convenient integral white background is to cut a ring of clear 13mm pvc tubing thin enough to fit through the drop checker neck (about 3mm)and push it into the bulb. The tubing will turn white in a day or so and provide a good viewing background. If it discolours slightly over time soaking it in a mild bleach solution will restore it to white. Be warned though once inside the bulb you won't be able to get it out again. Worked for me - still using my original dc after several years.


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