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co2 help I'm a little confussed

tovtm

Member
Joined
2 Jan 2011
Messages
249
hi at the moment my tank stats are as follows

125ltr tank which house my discus breeding pair, corgys x6 tetra x 16 and two bolivian rams.
have two 4' t8 40w
cat litter substrate 2" deep
CO2 lights on checker is green-light green on at 12pm off at 9pm
lights on at 4pm off at 11pm
dosing EI Mon-fri (Mon,Wed,Fri 50ml, Tue,Thurs 25ml trace)


I keep reading co2 checker should be lime green when lights come on however mine is just between about to come out of a dark/lightish green when lights come on. so should I turn needle valve up or extend the time it comes on even earlier? reason I'm confused is it already seems light my co2 comes on a long time before lights come on compared to most peoples so i don't know which one I should change timer or needle valve,

thanks in advance. Tom,
 
It's a balancing act.

Turning up the gas instead of increasing gas time prior to lights on and you could end up with toxic concentrations of co2 during the photo period.

Increasing the pre gas time by half an hour would be the safer option although you may have to tweak both to get where you need to be.

Remember that the drop checker is only an indication. I've seen some photo's with yellow drop checkers with livestock in the tank. A lot would also depend on your method of diffusion of the co2 and how effective it is.

Looking back at this thread, viewtopic.php?f=3&t=17995&start=10 your also running higher temps which has a negative impact on the solubility of co2.
 
diffusion is going through a up atomizer about three inchs after the external filter then going through a spray bar which stew he's across the whole length of tank, co2 mist always seems to look evenly displaced and I have spray bar holes horizontal facing front of glass about 3/4" to 1" away from water surface so I can see a slight movement on the water but nothing bad. hope this helps. also I did get told I was running higher temps and I've gradually declined the temp to 26 degrees is this any better?
 
The gas dissolves better at lower temperatures. That's why Soda Stream adivises to chill the bottles of water before use, to use less gas.

Your diffusion sounds ok. So it's back to extra time and injection rate. This is where you need to find the balance. As already mentioned, the safest way would be to start gas 30 mins earlier, than to crank up the injection rate although you will probably have to tweek both anyway.
 
on average what do you consider to be normal turn on of co2 before lights on? or dosent it matter just I know plants only start using co2 once lights are on
 
This varies. There is no cut n dry answer though most use around an hour or two prior to lights on, I had poor diffusion in my 60l and went as high as 3-4 hours to get lime green at lights on.

Water temperature along with diffusion and injection rates all vary. You need to make small adjustments and observe and readjust until you find the balance for your aquarium.
 
Personaly I would think lowering the temp with discus will upset them more than tweaking your gas a day at a time
I run a 500ltr with discus and use an up atomiser as well my gas comes on 2 hours before lights my dc is lime at lights on and temp is 84 so I chuck gas in but I increased over a few weeks until i hit the sweet spot
it's a slow process but worth the time
Matt


Sent from my iPhone using Tapatalk
 
this is exactly what I was thinking it's already 4 hours in front so would it be wise to maybe turn gas up a little but also make co2 come on a little later? I do understand about it's all tweaking but I would rather go in the right direction as in either turn gas up and come on a little later or just come on even earlier.
 
tovtm said:
on average what do you consider to be normal turn on of co2 before lights on? or dosent it matter just I know plants only start using co2 once lights are on

The plants start using CO2 only when lights are ON, but by then they are pretty hungry already and would love to have a real good amount of CO2 in water. Thats the reason why its advised to start CO2 early enough so that given all the flow/circulation issues, plant-configurations etc, the tank has enough time to 'uniformly' acquire enough CO2 throughout its volume.

In your case if the gas is ON 4 hrs before lights, then you should check the flow, dead spots etc.. Water has a pretty high friction and tries to maintain the flow structure imposed by our filter-outlets. So its pretty easy to end up in dead areas where theres no circulation, or semi-dead areas where the leaves sway gently, but still the flow rates are small enough to significantly reduce CO2 reaching those places.

(As an aside: I once used fluid zeolite as a tracer of my water movement to see if the flow uniformly covers the tank volume. Thats a nice/easy way to check it.)

-niru
 
tovtm said:
hi at the moment my tank stats are as follows

125ltr tank which house my discus breeding pair, corgys x6 tetra x 16 and two bolivian rams.
have two 4' t8 40w
cat litter substrate 2" deep
CO2 lights on checker is green-light green on at 12pm off at 9pm
lights on at 4pm off at 11pm
dosing EI Mon-fri (Mon,Wed,Fri 50ml, Tue,Thurs 25ml trace)

Tom,

Six corgis in a 125l tank? Should the RSPCA be told? ;)

Mark

(sorry, couldn't help myself!)
 
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