In my experience the bottle pressure drops rather quickly over a few days. In addition, I found that over time the injection rate increased with a quick co2 dump at the end of the life of the bottle.
Mike if you drop checker is turning yellow - that too much gas if its turns blue - not enough gas which is bad for the plants but good for the fish . As Clark stated when the bottle become low on pressure the Bps rate increases and I have heard the the remaining gas dumps its self - touch wood mine have never dumped the gas into the water column - I use JBL regs / solenoid valves. Regards paul.
If the fish can tolerate it, there's no problem with a yellow or near yellow DC. DC's aren't perfect, so watch your livestock...
Hi Mike I'll agree with that, mine's virtually yellow all the time now during lights on after finally sorting out my CO2 delivery. Of course the plus side of this for the fish is, my tank looks like a jacuzzi just before lights out so plenty of O2 for the fish . You'll end up just using the drop checker as a rough guide, and let's be fair, your looking at a moment in time some 2-3 hours ago anyway but it's the best we've got for now. Like yourself I was ultra cautious at the beginning with the injection rates (boy did I pay for that with the dreaded BBA, but that's all sorted now ). I was quite surprised at just how much my injection rate has gone up since I started, although the extra plant mass has got a lot to do with that. As JamesM says, watch your livestock, it's the quickest guide you'll ever have. With regards to your opening post, I have found that when the high pressure side starts to drop, it starts dropping very quickly (within a day on my 180l), and I then get erratic bubble rates, so I change it then. Fortunately I've never had this mysterious 'CO2 dump' that I've read so much about . Good luck. Chris
If your dc is changing to yellow with very little gas I would check your 4dKh solution. I had a faulty batch which changed to yellow very quickly.
Hi Mike I only use 1.5ml of 4dkh and 2 drops of the test solution. I think that's what my instructions said when I started. :? Works for me . Chris
