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Tuesday, 4 June 2013

Its been a while… CO2

I've been a little slow posting as of late, but i have by no means been slacking on the aquarium side… with perhaps the exception of my reef tank, which is still full of fresh air…

With respect to my little experimental planted tank though, things have changed drastically!

Ill start with CO2.

For a while now i have been skirting around with this subject, starting with the commercially available liquid carbon sources with varying degrees of success, and if i had to recommend one of these products, it would of course be Seachem Flourish Excel.

Following a crash and demise of most of my planted stock and a subsequent algae breakout which i put down to a factor of changing some of the products i was using, my LFS suggested using CO2 to try and bring the tank back to its better days.

This started by trying out a biological CO2 system from JBL called the ProFlora Bio 160. While it did create CO2 gas for a reasonable amount of time, and the kit itself was generally well made and nice and simple to use and install. It just didn't have the power to put out a sufficient amount of CO2 gas. It barely even registered on the pH readings, let alone on my drop checker.

It could have worked differently if i had used a different mixture, or at least a different type of yeast other than what is provided in the JBL refill kits, and i did contemplate building a larger bio CO2 system to see if it could become much more capable. But the space for the vessels and the potential mess lacked any appeal.

So with that i effectively shut down the bio system.

2013-05-18 10.05.19

I decided to just get my finger out and sort out a pressurised CO2 system.

For a start i found a few reasonable suppliers for CO2 “pub gas” and eventually contacted Terry from Yorkshire CO2 Gas who sorted me out with several 14lb bottles for £65 each. A bargain compared to some of the “aquarium specific” CO2 bottles that range into the £100’s for around a third of the capacity!

2013-05-16 18.11.30

As i already had a regulator, all i required was an electronic solenoid to control the gas flow, and i would recycle the non return valve and Taifun diffuser that came with the JBL Bio 160 kit. The solenoid itself will be controlled through timing and pH using the installed Neptune Systems Apex.

The solenoid, i managed to pick up from Wharf Aquatics, made by Sera and has worked flawlessly so far.

Only minor issue was the Euro plug, but easily rectified with a good quality adaptor.

Sera CO2 Solenoid 

I had a few teething issues to start with. Mainly due to me being green when it comes to using this kind of setup. The regulator i had, included a needle valve that was installed directly onto the regulator output.

I ran some tube from the bottle to the aquarium and installed the solenoid at the tank end so it could be controlled by the Apex. However when the solenoid opened, if it had been closed for some time, i would get a massive surge of CO2 bubbles through the diffuser, making anyone in or out of the aquarium jump!

I soon learned that the needle valve was supposed to be at the other end, and luckily had the parts i needed to dismount it from the regulator and relocate it to the tank end.

With that complete, the surge issue was completely removed.

A bit of fine tuning and adjustment on the working pressures and the needle valve adjustment, and i have achieved a nice and steady 2 bubbles per second flow.

And low and behold i now have an excellent and sufficient source of CO2!

My plants seem to breath a sigh of relief and really look to be coming on strong now with an abundant source of free carbon going round in only around a fortnights worth of usage.

I have been using a combination of visual monitoring on the drop checker, and pH readings based against the KH in my aquarium water. I did have some people saying i had gone over the top (as if i would!) and just have a fancy way of suffocating the fish. But i have researched and took information from various sources and actually have good correlation between the pH, KH and what my drop checker is telling me.

But then, this is a hobby where opinion will be divided and people will stand their ground!

A screen shot from the Apex iPhone app…

Neptune Systems Apex pH iPhone Graph

My CO2 comes on and hour or so before the lights, then maintains a 6.70 to 6.80 pH until the lights go back off.

Although it doesnt show too well, i now have a nice green colour in the drop checker for pretty much the first time since i used the small 88g CO2 cylinders on the TMC system.

JBL CO2 Drop Checker

I continue to experiment with the CO2 injection, but fully relieved i have got it installed. At the rate i am using the gas, my 14lb bottle should last a considerably long time, and should be a worthwhile investment in lieu of the prices for liquid carbon sources.

I have some new lighting over the tank and have started a new dosing regime, which i will elaborate on during the next few posts. With these three combined together i am hopefully going to find a balance that keeps everything growing in a lush way.