CO2 setup question

[pjcook]

I am setting up a new planted tank in an Aquareef 300 and will be usiong CO2 for the first time.

I have purchased all of the kit, Sera bottle, Dymax-122 regulator, diffuser and bubble counter.

My question is, can I set up the diffuser in the Sump rather then in the tank?
I am loathe to add equipment in the tank if I can avoid it.

[swifto]

hi,from what i've herd u can,but someone with more experience mite no better.

[Nev]

Have just (today) done the exact same thing.
I've used a CO2 reactor instead of a diffuser in the sump. just put a small power head to drive it in there.

[pjcook]

OK, so should I place the diffuser before or after the bio balls?

[swampy1972]

Aeration is the enemy of a Co2 system, meaning you want the maximum time for Co2 to dissolve in to the water column before it falls through the media again (I take it you have a wet/dry sump).

The action of the water falling through the media releases the Co2 to atmosphere - wasting it.

Place the reactor in the area adjacent to your return pump in the sump. Ideally, you'd have it on the line out of the return pump with Co2 injected directly in.

Have a look on the aquariumlife forum to get some great info on planted tank and Co2 setup

[pjcook]

Thanks, I will set it up next to the return pump and see how it goes.

[Nev]

The reactor will dissolve most of the CO2, just having fine bubbles wastes most of it and it just goes straight to the surface. Reactors don't cost much. $25 or so and do a great job.

[pjcook]

What is the difference between the reactor and a diffuser? I thought the diffuser allowed the CO2 to dissolve before being released into the water

[swampy1972]

What is the difference between the reactor and a diffuser? I thought the diffuser allowed the CO2 to dissolve before being released into the water

A reactor is a larger unit, generally external to the tank though not always, that has return water flow from the filter passing through it on the way back to the tank. It also has items suh as bio-balls, noodles etc that allows the gas to be broken up to aid in absorption.

The key to their design is that the water flow is directed DOWN and the gas is injected toward the top of the unit. This sets up a situation where the bubbles that are trying to float up through the reactor, are countered by the downward waterflow suspending them in the reactor while they are broken up by the bio-balls and gradually dissolve.

You need to get a unit suited to your filter flow rate, or run it separately to you filter on a dedicated powerhead/pump in order to establish the equilibrium between the upward trend of the bubbles vs the downward flow.

They are far more effective than diffusers because of the action of holding the gas in the chamber..

Diffusers on the otherhand are a simple ceramic disc that breaks the gas into 'micro-bubbles' in the hope that they dissolve prior to getting to the surface. Some include a small spiral below the disc to provide more time for the gas to dissolve prior to going through the disc. The ones I've used to date do not seem that effective if you're hoping to dissolve 100% of the gas.

If you chose a diffuser, place it below the filter outlet so that the rising mist of bubbles get caught in the flow and hopefully dissolve more for you.

Clear as mud?? :P :lol:

[pjcook]

OK I have a DYMAX DF-102 Diffuser which has the following descrition:
DF-102 DIFFUSER


DF-102 DIFFUSER

Combination of separating disc with ceramic atomizer to create the 2 in 1 Co2 reactor.

Double efficiency of diffusing up to 98% of Co2 into the water.

Easy installation and maintenance.

For up to 100~180cm tank.

Looks like it fulfills the description :)

[Nev]

Try it and see, but if you can see bubbles from it floating to the surface it's not getting 98% diffusion.

[pjcook]

OK I have placed the diffuser/reactor into the sump, so far so good....

Now, I have heard that 3 bubble per second during the lighting cycle is the accepted rate, is this correct?

I have it running at that rate, and I cannot actually see any bubbles at all in the reactor, if i open up the valve I do see bubbles so the co2 is flowing and I cannot see any leaks in the lines.

My tank is 300 litres so what rate should I be adding the CO2?

[swampy1972]

Does your regulator have a solenoid or are you turning it on/off manually at the reg each day?

If it has a solenoid I'd recommend getting a cheap Ph controller. This is the one I use and it makes operating Co2 really easy http://www.ebay.com.au/itm/Weipro-PH-2010-ph-meter-value-controller-Fresh-Salt-/400260839127?pt=AU_Pet_Supplies&hash=item5d3167b6d7

If you don't want to go with a controller, you can simply run the solenoid on a simple light timer. Most that do it this way tend to turn the gas off about 30min prior to lights out, and bring it back on about 30min before lights on. The reason being that the gas levels will be sufficient for the last 20min of the day and allows it build up prior to the plants demanding it in the morning. You need to remember that plants only use Co2 during the photo-period, after that they actuall give it off.

If you're running it manually or with a timer you really need to buy a drop checker so that you can set the correct bbs rate, otherwise you run the risk of saturating the water column with Co2 and gassing your livestock.

Until you get a drop checker I'd start slowly with 1-2 bbs just to be on the sfae side.

The amount of Co2 required really depends on the type of plants you're keeping, so it sounds like you really need to do a bit more research on the requirements of your plants and the setup of your system. Co2 systems can be dangerous to you and your livestock so it really pays to do your homework. I've seen plenty of tank setups that are equipped with it that don't actually 'need' it, so they end up a waste of time and money and actually cause more hassle than benefit.

[pjcook]

Thanks Swampy, I actually have a GHL aquarium computer from my Marine days, so once the new PH probe arrives I can program it to do it all automatically.

I do have a solenoid on the regulator. Is a drop checker different to a bubble counter?

How do I set up the rate using PH as the guiding variable?

[swampy1972]

A drop checker gives you a visual indication much like a Ph test - it's glass bowl that has indicating fluid in it that stays submerged in the tank and changes colour in response to the Co2 saturation. Just do a search on EBay and you'll find plenty of cheap ones.
You'll also probably need a calibrating solution for your probe if it's not supplied with one to help setup the computer.
Since you're using a controller, the bubble rate "almost" becomes irrelevant since it's responding to Ph levels. With that in mind, I still tend to set mine for about 2bps to slow the rate of change when the solenoid opens. If you have a high bps rate your Ph will change quickly and possibly shock your livestock.

I hope that's easy to understand?? PM me if you need clarification,

[axl]

Hey Swampy,
hows things? looking at setting up a Co2 system on my 6x2x2 tank. Would these regulators work on our Australian co2 bottles??

http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=280697989243#description

Also are they any good??? they seem like a reasonable price and i would buy 1 of those ph controllers that you suggested and you use??

Have you had any trouble with your controller??

I could just diffuse the co2 with 1 of those co2 atomizer straight into my eheim 2217 couldn't I ??

Cheers Axl

[swampy1972]

Hey Axl.

The main point to any reg is to ensure the thread fits and AS (Aust Standard) thread because that's what will be on the bottle purchased in Aust'. If not, you need to know what thread it is and source an adaptor.
It would also pay to find out if the solenoid is replaceable should it fail, as many of the 'Asian brand' ones do (my Up Aqua one did). I purchased mine in from B and C aquariums in Sydney so it was an easy swap over.
I have nothing but praise for the Weipro 2010 that I use. It's a great little unit that's accurate enough for the hobbyist (like me :P) so I would recommend them.
For a 6x2x2 tank I would look at making a DIY reactor to reduce gas wastage. They're pretty straight forward and made from readily available parts. I'll PM you a link to a very good one. If you prefer to use a diffuser on the intake side of your canister, I'd recommend getting a good one like the Up Aqua inline diffuser. From all accounts they do a good job of diffusing the gas (as long as they're kept clean), otherwise you run the risk of getting a Co2 build up in the canister and you end up with a filter that burps/farts large Co2 bubbles into the tank. Running the higher concentration of Co2 through the canister has also been known to harden O-rings and impellers etc causing them to become brittle and causing leaks and component failures, so something else to consider.
Co2 setup is fun - ain't it :lol: :P

[axl]

thanks for the info swampy and sending me that link (when you do). How much was your regulator and solenoid from that shop????

Sounds like making my own co2 reactor would be the go and do you just run that through your eheim 2217 as well???