PDA

View Full Version : CO2 Issues ... Again



geowashlaw
02-13-2011, 02:04 PM
I'm about ready to throw my whole setup in the yard. I am still having trouble getting to 30 ppm. I built a Rex Grigg style reactor and that would get me there occasionally, but would not keep it there consistently. I've switched back to my Aqua-Medic reactor for the past several days and have it running on my SMS122 pH monitor, but it hasn't gotten it up to 30 ppm yet. I'm at the end of rope with this thing. My tank is covered in green hair algae all over the plants and equipment. Do I need more than one CO2 setup for a 120g tank to get enough CO2 in the water or am I missing something else?

chrisfraser05
02-13-2011, 03:37 PM
the PH monitor is the problem!

Throw it out and just set it with a drop checker.

I'd advise getting a timed solenoid and having it come on a few hours before the lights and off with or just before the lights though.

The algae is caused by the fluctuating CO2 which is all down to the PH monitor.
Ph monitors are slow to respond, by the time it sees the change in ph and adjustes the CO2 the actuall drop could be as much as 10ppm. You may be having constant swings of CO2 throughout the day which in reality isn't good!

rich311k
02-13-2011, 04:40 PM
30ppm is a great goal but less as long as it is steady is not bad either. You very well might need two reactors to get to 30ppm. I second using a drop testor and go slow. Change it once a day and slowly get to your goal in a methodical fashion.

dbosman
02-13-2011, 04:56 PM
30 ppm in a 20 is easy.
30 ppm in a 55 is doable.
30 ppm in a 120 is difficult.
You may have to change your expectations rather than your reactor.

I'd scale back on the lights for a while, consider a careful over dose of Seachem Excel, and manual algae removal.

**********************************
Is the probe on your pH meter correctly calibrated? and actually working? They need to be replaced roughly once a year.

geowashlaw
02-13-2011, 07:17 PM
Thanks for the advice all. My CO2 is running all the time. My pH never hits the target. It doesn't even get there when the lights are off. I have a drop tester in addition and the fluid is never anything but blue, even when the CO2 has been running for hours with the lights off.

I have my regulator set as fast and as hard as it will pump already, so there's no increasing what it is pushing.

As for the algae being caused by the pH monitor, that's just not possible because I have not ever had the pH monitor on this tank. I set the tank up in August and was just using the reactor I built and having the CO2 run only when the lights are on.

You say it is caused by the fluctuating CO2, but short of running the CO2 24/7, whether you are using a drop checker or a pH monitor, then the CO2 is going to fluctuate. Even your suggestion of a time solenoid, which is basically what I was doing by having my regulator on a timer, there are always going to be fluctuations. So, I fail to see how having one method of turning the CO2 on and off is going to be superior to another method. But, like I said, there's no way that the pH monitor is the problem because I only introduced it several days ago.

geowashlaw
02-13-2011, 07:23 PM
30 ppm in a 20 is easy.
30 ppm in a 55 is doable.
30 ppm in a 120 is difficult.
You may have to change your expectations rather than your reactor.

I'd scale back on the lights for a while, consider a careful over dose of Seachem Excel, and manual algae removal.

**********************************
Is the probe on your pH meter correctly calibrated? and actually working? They need to be replaced roughly once a year.

The probe is brand new. I just got it this week. I can't do Excel because I have Vals in the tank ... I had thought of that and I'm trying to consider whether getting rid of the algae is worth losing the Vals ...

funkman262
02-14-2011, 06:39 AM
I have a moderately planted 90g tank and my drop checker remains yellowish green using DIY CO2 and two Elite Underwater Mini Filters. I don't see why you wouldn't be able to achieve it in a 120 using pressurized CO2. Try adding another reactor and have them run on both sides of the tank. What kind of filters/powerheads are you running? Is there anything disturbing the surface? Do you have any leaks in your system? I'm sure you'll eventually be able to get it figured out and take care of the algae. In the meantime, I'd suggest getting some ottos, SAEs and flagfish for keeping several types of algae in check.

geowashlaw
02-14-2011, 06:53 PM
here's an interesting suggestion from my dad (who is what we call a redneck engineer ... ) he suggested that I clip the CO2 line to the intake on my Mag 9.5 pump with one of those clips that you use to clip the water line in your toilet tank so that the Mag sucks in the CO2 and pulverizes the bubbles as it returns the water to the tank ... anyone ever tried this? Thoughts? I think I'm going to try it because those clips are about 50 cents at Home Depot ...

rich311k
02-14-2011, 06:55 PM
I have disperesed CO2 like that for years, never had a problem.

chrisfraser05
02-14-2011, 07:03 PM
some have done it with alot of sucess, others have had pumps fail because of it.

The prob is that as the bubbles hit the impellor blades they create a shockwave which can destroy or weaken them.

I've never tried it personally but it is a vaible method if you don't mind risking replacing the blades if the worst happens

geowashlaw
02-14-2011, 07:11 PM
Thanks guys ... I'm definitely going to try it then ... seems I may be making this whole process too complicated!

geowashlaw
02-15-2011, 07:33 PM
So, I tried putting the CO2 feed directly into my Mag intake. It helped a bit. It lowered my pH by .4. My drop checker still showing blue. So, I'm off to the races again to figure out a good reactor. After consulting with my brother who has lots of background in math and science, he thinks the reactor I built was inefficient. So, he's working me up plans for a new one based loosely on the Rex Grigg model.... and I'm considering a second tank/regluator set up so that I have two input lines.