Checking CO2 Sysstem

[orgetorix]

OK....I'm just settin gup my 300 Gallon planted tank and am in the process of setting up the CO2 system. How long should it take for the CO2 to be fully diffused in my tank. Seeing as how this is a huge volume of water, shoudl I wait a day, two, or a week before I can test pH and be relatively sure that the reading is accurate. If I check an hour after hooking things up, it may be that the CO2 hasn't had a chance to mix in with the water. Thanks for your help.

[djlen]

Questions:
Is this a pressurized system?
What is the pH and kH of the tank now?
What is your bubble rate?
How are you diffusing the gas into the tank?
What kind of filtration are you using?

Depending on the answers to the above questions you may have a stressful situation for your fish which needs immediate action.
CO2 injected under the proper conditions will start to drop pH in minutes. It needs to be monitored hourly during initial set up and adjusted if necessary.

Len

[orgetorix]

pH = 7.4
kH = 6º

It is a pressurized system. I am using a reactor from plantguild with a small Rio powerhead on top. The filtration is the simplicity plus wet/dry from Tenecor www.tenecor.com

I'm not worried yet as I have no fish or plants to speak of....I would like ot get everything set up and understand it all before I add anything living. Thanks for you help.

[bobalston]

Make sure your wet/dry filter is sealed or you will likely lose much of your co2 there.

Bob

[125gJoe]

Link: CO2, KH, pH Table (http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm)

Use this Chart to see how much CO2 you have. I'd check twice daily (morning and nighttime), until you have it under control..

[djlen]

Wet-dry filters are not the best for use with CO2. As Bob said in his post, make sure the system is sealed. They, by nature tend to cause problems keeping the gas in the water table.
If you checked the tables posted above you will see that the gas can/will affect the pH quickly.
How much and what type lighting are you going to be using?

Len

[orgetorix]

Thanks for all your guys' help. I have found that I can get the pH down to 7.0 with what appears to be about 15 bubbles per second. If I up to what I estimate to 20 bubbles per second, I can get pH of about 6.8 I am using 6x96W compact flourescent so 576W per 300 gallons or 1.92 WPG. I know that this seems to be a really high bubble rate compared to others I've heard, but I don't really know for sure. There could be a large amount of gas off due to my filter and I'm not convinced about the effectiveness of my reactor. What do you guys use/recommend? I'm thinking of investing in a better reactor, or maybe using an old canister filter? At my current bubble rate, how long can I expect a 10lb bottle to last? I don't mind having to fill it up more often, but would like to be ready for when an approximate refill time would be. Thanks again.

Mike

[djlen]

Yes, that is a very high bubble rate. It certainly wouldn't be acceptable to me, but if you don't mind the re-filling so be it.
I would use some soapy water and check all the connections from tank for leaks. If you don't find any I'll be surprised, but not too surprised as many people have this kind of issue with wet-drys.
It's hard to estimate the flow rate on an individual CO2 tank, but I would not be surprised if you have to re-fill in a month or two. Maybe sooner.
Keep an eye on your regulator. When the gage starts to drop, it's running low. It should say 850lbs/sq in. when full. When it drops to 600lbs. get it filled. When mine gets that low I have a pound or less in the tank. Letting it get lower, for me risks a gas discharge into the tank that could kill fish.
If I had a cannister filter around I'd use it in place of the present one. With a kH of 6 and a cannister, I'd estimate your bubble rate for the same affect would be about 2 - 4 bps. That, of-course assumes you have no leaks in the CO2 system.

Len