Too much CO2 with DIY possible?

[SecretSquirrel]

Hey guys, newb here. I've finally decided to go with live plants and am learning a lot reading your threads and browsing the net. This site is great and I hope to become a useful contributing member down the road. For now though, I am assimilating information and need a little advice about my DIY CO2 injector. First the facts, then the question. You can skip straight to the question if you please.

My sitiuation:
-Tired of dull plastic plants, and cheap Walmart ornaments in my 55 gal tank; want a more natural look. I love the look and atmosphere of living plants
-Just lost my buddy of 6 years, an 11 inch tiger oscar. Going with smaller fish now. Seriously considering discus, angel, and gourami.
-Prepping tank now. Tossed out my plastic plants and synthetic ornaments. Got some plant substrate, water is cycling now. Lighting is in the works.
-Found a nice article on DIY CO2 injectors and have one running in the tank.
-I am practical, and cheap to a degree. I don't mind investing on necessary expensive equipment, but if similar results can be obtained from DIY project, I will spend a weekend saving myself $20. After all, it's a hobby and I take pride in doing things myself (and hate getting ripped off).

Question:
I removed the aerator stone and got a true bubble count of 88 bubbles per minute. The pH of my tank has not changed in the 24 the CO2 has been running...holding at a nasty 7.6. So I'm wondering is this too much CO2? I've seen posts here where people are happy with 4-6 bpm. Having a fair understanding of biology, chemistry, and botany I am assuming that my primary concern in too much dissolved CO2 is lowering pH via production of carbonic acid. As long as my pH does not drop below desirable levels, isn't more CO2 better for plants?

I have three 2L bottles hooked up in series with T connectors, all converging to a tube with a stop valve that then runs directly to the substrate and is passed through an aerator stone. As such, I do have some control over decreasing the CO2 flow by disconnecting extraneous bottles.

[tnsser]

I am fairly new too. I do know that a drop checker would help you a lot.

[Darkblade48]

Personally, DIY CO2 on a 55g tank will become expensive in the long run. You will do much better by purchasing a pressurized CO2 system instead. Your bubble rate is quite low (about 1.46 bubbles per second). Most people are content with 4-6 bubbles per second, not per minute. This may be why your pH is not dropping very much. In addition, don't forget that you will have natural buffers in the water that will prevent the pH from shifting much.

Your primary concern is unfounded; the pH drop due to the dissolution of CO2 into water (and thus forming an equilibrium with carbonic acid) will not harm your fish, as long as it is gradual (which it is, in the case of CO2 injection). Your pH will also not drop below a certain value (I forget the precise number), as it is chemically impossible for CO2 to lower it beyond this value.

As tnsser mentioned, a drop checker will also help immensely in determining whether you have correct CO2 levels (~30 ppm) or not.

[james0816]

wow...4-6 bubbles per second? Mercy! And here I thought mine was doing just fine. I'm not sure of the exact bubble count as I never really look at that. I just look for the green in my drop checker.

[redfalconf35]

I have overdosed DIY CO2, but it's really hard... I hooked up 2 "Simply Orange" orange juice bottles (just under 4L total) to my 29g and just put yeast into the orange juice. Those fish were none too happy with me for that. Anyway, to the meat of your question. If you have no fish, crank dat CO2, because the plants will love it! A pH swing induced by CO2 isn't the same as one caused by other reasons, so fish and plants are more ok with that happening.

[SecretSquirrel]

I'll pick up a drop checker today thanks for the advice everyone. Yeah, 4-6 bubbles per minute seemed pretty low to me, but like I said I'm totally new to having plants in a tank. Darkblade, I think I am going to take your advice and go with a pressurized system. It seems I need to have at least twice the CO2 output I'm currently getting and that isn't very practical. The price of making the mixtures and time consumption are too great. Plus, there is obviously a huge lack of control with the 2L bottle system. So this brings me to my next question, anything in particular I need to know before I make this investment? I found a site with a decent-looking setup, but as a newb I can't post links, grrrr!

[Darkblade48]

Here is a quick guide for pressurized CO2.

Here are the things you will need:

CO2 Tank: I believe this is obvious. Buy the largest tank that you can afford/that you have the space for. This is because (say) a 20 lb tank is not much more expensive than (say) a 10 lb tank. In addition, refill costs are either the same or nearly the same despite the 20 lb tank being twice as heavy as the 10 lb tank.
Regulator: This will reduce the tank pressure from ~800 PSI to a workable delivery pressure (most people set it between 20-30 PSI).
Needle Valve: This will further reduce the working pressure to an even lower rate (i.e. bubbles per seconds).

Some more "optional" equipment (in quotations, because in reality, they are needed, but are more for "safety")
Check Valve: You don't want a back siphon to start and have water destroy your regulator build

Optional, but highly recommended equipment:
Solenoid: Allows you to put your CO2 on a timer, so that it will turn on and off automatically.
Drop checker: When used in conjunction with a 4 dkH reference solution (can either be bought or made; I work in a lab, so I make my own), it will allow for "at a glance" levels of CO2 in your aquarium. It is possible to DIY one yourself to save on costs.
Bubble Counter: This allows you to visually check the bubble rate of your injected CO2 "at a glance". I am tempted to put this in the section below, as personally, I do not even use a bubble counter. In addition, it is possible for you to DIY one to save on costs.

Optional equipment, if you have cash to spare:
pH controller: Allows the constant monitoring of pH and can control the injection of CO2 (when used with a solenoid).

Note: If you purchase each part individually, you can get a better setup for the same price (or the same setup for a cheaper price). This is especially true if you bargain hunt, waiting for the lowest prices on eBay/Swap and Shop forums.

[SecretSquirrel]

You really pulled through Anthony, thanks. Once thing that was preemptively frustrating was knowing if I tried to buy things individually I would invariably leave out some important component and delay my tank for another week. That list will help a lot. Thanks again!

Oh, and now that I have enough posts I can put up this link of the system I found for a modest price. I would be grateful to anyone with experience who could tell me if any part of this set-up is unnecessary or of low-quality. Looks reasonable to me.

http://co2-canisters.com/contents/en...FRESawodjxj_Mw

[Darkblade48]

I just realized I missed a few points in my above post, so it has been revised (I copied and pasted from a previous thread).

As for the link you posted, some people have had some problems with JBJ regulators, while others have it working fine. The stock needle valve on the JBJ (as with the Milwaukee, if you are looking at that regulator as well), leaves much to be desired, in my opinion.

In addition, from the setup you have linked to, I feel that the pH controller is entirely unnecessary (and as a consequence, so is the calibration fluid). Many people with CO2 do not have a pH controller and they get about just fine. CO2 resistant tubing is another marketing scheme, in my opinion. People often tout that silicone tubing is inferior in that it loses much more CO2 gas compared to their "resistant" tubing, but for the working pressures that we are using, and the relatively short distances we are using the tubing over, the amount of gas loss is negligible.

Finally, if you do not want to purchase the parts individually (i.e. advantage: you do not need to spend time and effort looking for parts, disadvantage: you may not save as much money as possible), then I would suggest the following sites to you:

http://www.greenleafaquariums.com/co2-regulators.html
http://sumoregulator.com/
http://www.bestaquariumregulator.com/CO2.html

[SecretSquirrel]

Thanks again, Anthony. I've been reading some reviews on the JBJ regulators (and yes you were correct in assuming I had also been pricing Milwaukees too) only to find many people agreeing with your assessment. It seems the needle valve often goes soft requiring multiple daily adjustments to regulate the bubble count--no thank you. I won't worry about the pH sensor either as per your advice. I still have a lot to learn, and just want to make sure I have a stable tank environment before adding living creatures. You've been a great help!

I'll be setting up a profile so all can see as my tank progresses.

[bherren1]

I bought an AZOO regulator online and it came with a cheap-o needle valve the wouldn't remain consistent. I had to replace it with a Fabco NV 55 needle valve. After you add up the prices for the equipment and shipping I would have saved my self $20 and 3 1/2 weeks worth of headaches by paying a bit more upfront and getting a quality regulator. Lesson Learned: With planted aquariums you can go cheap and cut corners with some things and sometimes you have to bite the bullet and get the best equipment you can buy. +1 on Anthony's recommendations for some nice regulators.