Maintaining peak c02 levels.

[Ady34]

Hi,
i have always had difficulty in maintaining c02 at a good all round level throughout the photoperiod.
Im currently experimenting with c02 to try and maintain peak levels (regards livestock) throughout my photoperiod without distressing the fish. I understand the light, c02 relationship and this is purely based on maintaining a level of c02 which will the suit the fish, then adjust lighting as necessary for the plants health.
Im currently starting injection 2 hrs pre lights on to get to a level of c02 for lights on which is at the maximum of fish tolerance without distress. If i leave this injection rate to continue throughout the photoperiod, levels rise further and the fish are effected. I have tinkered endlessly throughout several tanks and cant seem to find the happy medium. I am now experimenting using my timer and solenoid to switch c02 off/on at 15 minute intervals for the rest of the injection period which stabilises the ph (and c02) at the peak level. Im using an inline diffuser which creates a mist, but also gives good levels of dissolved gas.
Are there any negative effects from doing this? Im guessing if the dissolved gas levels are good the plants will still have access to c02 during the 15 minute periods without the mist?
Does anyone else do this or have experience of this method?
Cheers,
Ady.

 

[Andy Thurston]

I though about doing this but ended up injecting at a slower rate starting 3 hours before photo period and ending 3 hours before lights off.

Reading cegs many posts about co2 he says plants need the levels of co2 more at lights on and not so much towards the end of photo preiod.

I suppose your method is more like using a ph controler in terms of how the gas is delivered to tank
I dont use an inline diffuser but inject co2 via a venturi in the power head supplying the spray bar which gives me a good ph drop and some fine mist in the tank
Also i have no live stock as yet but am interested in how you get on with this method of optimising co2 throughout the photoperiod for when i add livestock
Im also concidering buying a very high quality needle valve and starting injection 4-5hours before lighs on

Andy

 

[Iain Sutherland]

Hey ady, just my 2 bobs worth...having just started using an inline diffuser again on the 60 id forgotten how much harder i find it to get a flora/fauna balance than via a reactor. Im only now just starting to find the happy zone and that is by starting 4 hours before at a very low bubble count and off 3 hours before the lights. I guess in this way it is similar to 24hr co2 in that concentrations arent too high but are stable and consistent. Even so the atomiser will go in the next week or so.
I dont see any reason why having it timed to go off from time to time wouldnt work, my only concern would be BBA from fluctuations?? However im only speculating...

The inlines atomisers are very popular but ive always had trouble with them, dont get me wrong i know it is me at fault not the product as scapes like george's attest but i really find the AM1000 far easier to use and achieve low tech levels of behaviour and activity from fauna while supplying the plant needs. As a bonus you also never need to worry about the atomiser clogging if you plan to keep the scape long term.

 

[jacaranda]

I considered using a timer that way too but have never got round to it so far .

I found whats best for me is a slower rate of injection starting earlier. Therefore the co2 stays in the safe zone for the fish for longer before climbing too high.

 

[Ady34]

Thanks guys.
My theory is based purely on getting optimum levels for lights on which means co2 being right at the uppermost concentration at that point. Even with a longer slower bubble rate I still had difficulty with fauna throughout the photoperiod as concentrations rose. This way I'm hoping to have co2 the best I can for lights on without rising and causing discomfort to the fish at any point during injection. I just really struggle to get it balanced for the whole time so I'm hoping this will work and be an answer to a happy tank
Iain, bba could be an issue but I think off gassing is so slow that hopefully 15mins on/off will be negligible, but just enough to maintain a level. Somebody may have first hand experience though and be able to shed light. If not I suppose ill be the guinea pig
I chose inline to try and get the best of both world regards co2 availability, both dissolved and direct contact but one day I will try a reactor if for no other reason than bubble free
With reference to ph controllers, it is a similar concept but without the failings. Being on timer im not waiting for the tank to react before injecting again so it cant be fooled by other sources of acidity. Its been quite interesting monitoring ph over several days. If i didnt water change for 2-3 days the ph drop would be 0.1ph less, im guessing due to the effect the seiryu stone has on KH, masking the effect of the co2 slightly?
I'm having a slight amount of filamentous algae at the moment which is a clear indication of co2 deficiency/too high a light intensity. Being as I can't increase co2 any more as I've found the limit that leaves distribution and light. I'm not buying a whole new spraybar system just now so may have to look at light, however I'm going to weather it for a little while hoping it may be remnants from the old tank.....wishful thinking
Really could do with a par meter too to get a full grasp on what's going on. I know the plants don't lie, but par and ph will help in identifying what needs addressing. Would be really interested to see with the hardscape layout etc what the par difference is between the fluorescents and the halide as the halide looks dimmer to the eye in the tank...but there is more shadowing effect. This may be a better choice if that is the case.
Cheerio,
Ady

 

[Iain Sutherland]

I'm guessing you have tried increasing surface movement along with earlier start time. Takes a little longer to build up to the desired level but helps to stop the steady increase through the day...
Ill be interested to see what happens running with breaks, keep us informed Ady.

 

[Aron_Dip]

Dont lol to loud .... But whats stopping you from having x2 Needle valves and x2 solenoid (into the same diffuser). 1st setup to go on and off for say 2-3 hours until lights on(or whats needed to reach optimum at lights on) and 2nd to come on at lights on at a lower rate to keep it topped up? If you understand that at all lol ..

Cheers ears

 

[Andy Thurston]

Dont lol to loud .... But whats stopping you from having x2 Needle valves and x2 solenoid (into the same diffuser). 1st setup to go on and off for say 2-3 hours until lights on(or whats needed to reach optimum at lights on) and 2nd to come on at lights on at a lower rate to keep it topped up? If you understand that at all lol ..

Cheers ears

If you run 2 filters that sounds like a good plan, certainly worth an experiment before laughing off. it could be problematic through one diffuser though

 

[Ady34]

Dont lol to loud .... But whats stopping you from having x2 Needle valves and x2 solenoid (into the same diffuser). 1st setup to go on and off for say 2-3 hours until lights on(or whats needed to reach optimum at lights on) and 2nd to come on at lights on at a lower rate to keep it topped up? If you understand that at all lol ..

Cheers ears

If you run 2 filters that sounds like a good plan, certainly worth an experiment before laughing off. it could be problematic through one diffuser though

I could do this as I have 2 filters, 2 diffusers and 2 co2 bottles with regulators and solenoids as originally I was going to run two. However it seems overly complicated when I can just use one system timed.

I'm guessing you have tried increasing surface movement along with earlier start time. Takes a little longer to build up to the desired level but helps to stop the steady increase through the day...
Ill be interested to see what happens running with breaks, keep us informed Ady.

Got a decent amount of surface movement, but its more based on past experience and constantly battling the same issue regardless. I could start fiddling with co2 again to try and get it balanced, but if this will work then it makes it easier and controllable.....the solenoid will be taking more of a hammering though, but its just doing what it's made for
Ill stick with it and see what happens. TBH it's nice knowing where the line is drawn regards fish tolerance and knowing its not going to rise further. It removes one more factor to worry about, then its just flow and light...happy fish, then adjust the rest to keep the plants happy too How people with very high light manage it i don't think ill ever know!
Cheerio,
Ady.