DIY CO2 diffusor question

[Biotoper]

Hi all,

I've just planted my first tank and I had a question about setting up a DIY CO2 system.

Pertinent info: The tank is a 75 gal SeaClear System II (I got a good deal on a used one), so it's got the filter stuff sectioned off in the back (essentially overflow goes through a prefilter which overflows onto a trickle tray over bioballs, which then gets pumped from a 350 gph pump out a manifold with several holes to the main tank). So really it's a ~60 gal main tank with ~15 gal in the back compartment. I've got 2x40W Chroma50 and 2x40W 6500K Daylight bulbs, and I just planted it today with Vallisneria spiralis, Rotala indica, Hygrophila difformis, and Cryptocoryne wendtii, and started fishless cycling it with ammonia.

So, back to the question, I'm planning on setting up 2 2L bottles of yeast culture. The tank came with an airline tube connected into the filter system near the base of the bioball compartment. It's called the Air Injection Nozzle in the instructions, to connect to an air pump to increase aeration to the bioballs if you want. However, I think I read on-line that some people inject their DIY CO2 into a bioball compartment in their their cannister to diffuse the CO2, so I thought maybe I could do something similar and connect my yeast bottles to the Air Injection Nozzle. Does this sound like a good idea or 1) the bioballs won't really diffuse the CO2 much, or 2) the CO2 may actually hurt my bacterial filter? If it did work, it would be great because there would be no need for an eyesore of a diffusor in the main tank (currently there's no equipment in the main tank) and the CO2-enriched water would being getting pumped throughout the tank.

I guess I can try it and see how much CO2 is dissolving. I have very soft water (I was planning on adding limestone to increase KH), so I should be able to tell pretty easily from the pH drop if it's working. If not, what type of diffusor do you recommend?

Sorry for such a long message. Thanks for your help.

 

[vega]

A 60gal need a presurise Co2 if financially permit. Inject CO2 into canister may increase the wear n tear as CO2 cause the internal of the canister more acidic. But depend on the material as well.

HTH

 

[TankGirl]

In your case, with this particular tank setup, it should work great to diffuse your CO2 into your bioball compartment. There is some risk of damaging a canister filter with CO2 diffusion, but plenty of people do it anyway, but for you that is not an issue. I would imagine if the gas does not destroy the biofilter in a canister then it would not in your bioball compartment.

I will agree that pressurized is going to be a much more desirable option, as you might require 3 2-liter bottles, and maintaining a steady CO2 concentration is going to be a chore with DIY for that size tank. It can be done (I've been doing it in my 55 for a year but finally got pressurized from Santa).

BTW, Welcome To AA, Biotoper!!

 

[vega]

yeah, welcome to AA.

 

[Biotoper]

That's good news! Thanks for the advice, TankGirl and Vega, and thanks for the welcome.

I understand a pressurized system is the way to go, but I'm trying to stay cheap, low-tech right now. Originally I was planning on getting a new 30 long glass tank which would have been easier to go low-tech with, but my used 75 SeaClear tank was such a good deal I had to grab it. All my friends/family that have aquaria have 20 or 30 gal max, so I have been getting a lot of oh ahs by its size when they come by.

TankGirl, by a chore, do you mean that the bottles will just be a lot of work to keep replacing the culture to keep CO2 production up, or will I run into problems with pH jumping up and down? I still need to go get a KH test kit, but my local water supply's water quality report says the KH is 40.2 mg/L or 2.2 dH. So I'm planning on upping it with baking soda to start off with and then using limestone in the filter tray onwards. I've read that a KH of 4 is ideal for a planted aquarium, but maybe I might want a higher target given my DIY CO2 system. Any tips?

Also, I should say that my tap water, although being very soft, has a pH of 9.3 (again this is from the report - I haven't directly tested my tap yet), so I'm hoping the pH will drop quite a bit with from natural CO2 uptake and CO2 injection.

Anyway, thanks again.

 

[TankGirl]

I'd go ahead and get some crushed coral in your filter and raise your KH before you inject the CO2, and you may be planning to do it that way but I like to clarify for others reading this. I find this method is by far simpler and steadier than using baking soda with each water change. I replace mine about once every 3-4 months or so.

The DIY is a chore for me because it is indeed hard to maintain a steady concentration, and hard to get the concentration up to decent levels. I keep multiple bottles and rotate the mixture so they all don't run out at the same time, and I have to keep track of which bottle is next in line to be replaced. Getting out the sugar, starting the yeast culture, testing the temp of the water, etc. is kind of a pain after a year, but if I skip it one week or delay I get a drop in CO2 and almost instant algae!

It is certainly cheaper than running pressurized, no question, and since you do not have high light over the tank the CO2 will not be so crucial as it is for me, with over 4wpg, so it is likely the simplest option for you.

 

[vega]

You must constantly ensure the bottle CO2 is fully active and you cannot delay to do maintainance to weekend as mention by TK any relax in maintaining the co2 bottle will cause ph to raise and algea.

Been there done that

I just install a presurise Co2 2 months ago after 1.5 years of using using bottle. Now i almost forget about producing co2 chore but simply concerntrate in taking care of the tank and of course enjoy the tank.



Its good to try out the bottle type as you really want to explore whether you really want the FW planted tank as invesment into presurise co2 and additional lighting is quite $$$ initially but once the presurise co2 and and lighting is been purchase there is not really other important $$$ item that can to be purchase.

HTH

 

[Biotoper]

Thanks. I've read suggested dosage rates for baking soda, but nothing for coral. Any idea how much crushed coral I should use for an X KH increase?

 

[vega]

if i am not wrong there is no dosage rate, just add CC into the filter as this method slowly increase the dKH when water wash through the CC (it may take few days to 1 week long).

 

[TankGirl]

I don't think there is a prescribed dosage rate, either, and I use about a cup and a half of it in my filter for my 44gal - it is an extremely gentle way to achieve the result, as the coral is literaly dissolved over time into the tank. It would be very hard to "overdo it" so put in as much as is feasible in the space you have to work with. I am sure there is a formula out there, but I have never found it necessary.

Vega, I have my new pressurized system sitting there until after this weekend (am going out of town) and because I got this for Christmas I skipped my regular yeast/sugar mixing chore and I can already see the algae forming! It is such a pain for my high light tank, and I can't wait to finally get my pressurized set up.

 

[vega]

It happened to me too. Sometime i was "lazy" a bit or outstation for work the next thing algea pay me a visit and the pH just when of the chart. it was lots of hard work down the drain as i find the garden i spend so much time on just overcome by the algae.

Finally during last same incident, only god know why, i just drove to the lfs a brought the presurise system (withouth the pH monitoring of course )...

Btw my tank is 3 wpg.

 

[Biotoper]

I finally got my test kits. My tank's pH is 8.1 (my tap is 8.4) and KH is somewhere between 2 and 3 dH (I think the KH titration kit wasn't a great purchase even if it was only $4).

I had started a fishless cycle ~12 days ago and expected I had a bit longer to go. However, thanks to my new test kit, my ammonia is reading about 0 (maybe a slight green tinge - say 0.05 ppm), nitrite is 0 and ammonia is ~30 ppm. So that might explain why my algae's been doing pretty well the last couple days.

So tomorrow I'm going to go get some Zebra Danios and some crushed coral to up the KH. I had a couple biggish coral rocks that I put in the tank. And then I'll set up my DIY CO2 soon after that.

My hope is that the coral will bring my KH up to around 5 dH and two 2L bottles of yeast can bring my pH down to 7. I'm going to stagger the two bottles a week, so hopefully the pH will drop slowly enough not to stress the fish.

Any additional tips? Thanks

 

[vega]

The adding of the coral might increase the pH, but it may be very little as your current pH is already quit high.

Refer to Greg's pH/kH chart, it will show the quantity of disolved Co2 better then any CO2 test kit.