New to CO2

[Luvlyjub]

I have been posting a number of questions as I set out on my journey in aquascaping and create my first proper planted aquarium and would appreciate some advice on my CO2 set-up.

This is for a nano 55L and I have been running the CO2 for a few weeks with plants only that are destined for a different aquarium. I believe that I have the settings just about correct with the drop checker (thanks to Andy Pierce and colour APP checker) and have been running a PH profile as well with following results:


So from what I have read recently on the Forum I have checked tap water profile and my tank running CO2. I seem to be hitting the right level but I was surprised by so much PH swing so quickly in the morning. Having read some good advice here and can I recommend the 2hr Aquarist Guides this seems normal as KH remains the same. Unless anyone can add anything here?

However, my concern is the rate of CO2 injection and bubble count to reach this. This is my first regulator purchase and I have a nano unit for convenience and space and I expected the guide of 1 bubble every 2/3 seconds for the size of tank. But I am pushing 2 bubbles a second to achieve my lime green drop checker! I appreciate that the bubble count is only a guide but does it produce nano bubbles as well 😀

 

[ceg4048]

However, my concern is the rate of CO2 injection and bubble count to reach this. This is my first regulator purchase and I have a nano unit for convenience and space and I expected the guide of 1 bubble every 2/3 seconds for the size of tank. But I am pushing 2 bubbles a second to achieve my lime green drop checker! I appreciate that the bubble count is only a guide but does it produce nano bubbles as well

Hello,
The best metric is the condition of the plants and the health of the fish in the tank. It's not worth losing sleep over bubble rate. This only means that you will have to refill twice as often as you had planned on. In any case you can always reduce the bubble rate and then observe the reaction of the plants and fauna. None of the numbers in the chart are scribed in stone. They are simply guidelines to help you get going.

Cheers,

 

[Andy Pierce]

Everyone's bubble size is different, so you can't directly compare, but my bubble counter runs about 2 bubbles per second to get to around 30-40 ppm CO2 in a 40L tank. For me, that works out to around 6 ml CO2 / minute. You can measure the volume if you invert a defined size measuring container over your bubble diffuser and time how long it takes to fill. Some good datasets here: CO2 used Database -needs your data

 

[foxfish]

However, my concern is the rate of CO2 injection and bubble count to reach this. This is my first regulator purchase and I have a nano unit for convenience and space and I expected the guide of 1 bubble every 2/3 seconds for the size of tank. But I am pushing 2 bubbles a second to achieve my lime green drop checker! I appreciate that the bubble count is only a guide but does it produce nano bubbles as well 😀

Lots of folk seem very surprised how many bubbles they require!
I think this misconception might come from outside of the forum?
It appears to me you might be adding a touch to much C02 for any fish you add in such a small tank, you say the tank is planted up, I bet you will see some good plant growth?
If the pants are flourishing you may be able to dial it down a bit If you intend to add fish, but if no fish, you could even turn it up a bit!

 

[Zeus.]

@Luvlyjub great start with doing a pH profile I have just posted this below in another thread but thought it may help/guide also

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A DC (Drop Checker) with a pH meter/pen or test papers, I trust the DC colour change as I have good flow in my tanks, if the flow is inadequate or set up incorrectly the DC colour change can vary in different parts of tank. Having good flow/turnover in tank resolves many CO2 related issues. Flow is King of the high tech tank. When my 50l gets overgrow the flow is hindered and my DC colour change becomes unreliable and CO2 levels fluctuate. A good trim resolves the flow and CO2 levels become good again

If your DC is green after two hours and the pH remains stable from lights on till CO2 off job done. However what is stable ? I aim for less than 0.1pH change from lights on till CO2 off - which is hard to achieve with BPS adjustments and takes many days/weeks to get it right.

Once you have a stable pH from lights on till CO2 off do not adjust the injection rate (BPS) again, which is a classic mistake of many folk new to CO2. The pre CO2 on time is the time it takes to reach your target/stable pH - if it takes 2 hrs 43mins that's how long it takes and adjusting the injection rate to shorten this time is a NO-NO.

There are ways of having better/faster control of CO2 injection, however with a single solenoid and 'normal' timers it isn't possible/advised

Unless you have very soft water or using RO/rain water, your dGH and dKH should be fine and the actual pH of your tank is irrelevant unless your livestock needs a specific pH range.

A 1.0 pH drop from CO2 on till lights on is the aim and will achieve 30ppm CO2 - Caution however as your tank may not be fully degassed from the day before. I take a glass of tank water and leave it 24hrs and use that as the base line pH off tank - eg pH off glass of water after 24hrs is 7.6pH then my target pH will be 6.6pH. It doesn't have to be 6.6pH you may be happy at 6.7 or 6.5pH.

Having a stable pH with good flow from light on till CO2 off is far more important/critical than the pH drop/[CO2]

 

[Luvlyjub]

Thank you all for this information.

So is the solution in the drop checker just measuring PH or is the colour change also subject to your KH?

For example my KH is seems to range between 7-8 based on accuracy of tests and timing of water changes using tap water in the tank. With Co2 I reach a PH of 6.85 and a nice light green DC. However, if for argument sake my KH was higher at 11 then at the same PH of 6.85 would the DC be yellow?

The other question is that my PH drop is 1.3/1.35 to reach my optimum, so is this too much and I should seek a drop to 7.2 as my starting PH is around 8.2?

Many thanks

 

[Andy Pierce]

The pH in the drop checker is only dependent on the concentration of CO2 in the aquarium water and not on anything else. That's its genius.

 

[Zeus.]

So is the solution in the drop checker just measuring PH or is the colour change also subject to your KH?

Like @Andy Pierce said

The other question is that my PH drop is 1.3/1.35 to reach my optimum, so is this too much and I should seek a drop to 7.2 as my starting PH is around 8.2

If your happy with the pH drop being over 1.0pH (which is considered the safe pH drop) then its fine or better for the plants, as long as your livestock can handle it. I use to do a 1.4pH drop and DC was nearly clear at times.

Another advantage of having a pH drop around or below 7.0pH is you should be fine with Fe EDTA ( which is the Fe chelate most complete ferts use) and there should be no need for Fe DTPA or Fe EDDHA

 

[ceg4048]

For example my KH is seems to range between 7-8 based on accuracy of tests and timing of water changes using tap water in the tank. With Co2 I reach a PH of 6.85 and a nice light green DC. However, if for argument sake my KH was higher at 11 then at the same PH of 6.85 would the DC be yellow?

The DC does not care what the KH of the tank water is. As long as you are using only 4DKH water in the DC whatever pH it registers will be a direct reflection of the CO2 concentration in the tank water. The ability to dissolve CO2 in water is independent of KH.

Cheers,

 

[Luvlyjub]

So if the DC is lime green it will always be in the range of around 30ppm CO2 no matter what my KH.

Are those charts showing PH/KH for CO2 something that I should not pay too much attention to then?

 

[bazz]

So if the DC is lime green it will always be in the range of around 30ppm CO2 no matter what my KH.

Are those charts showing PH/KH for CO2 something that I should not pay too much attention to then?

👍👍

 

[dw1305]

Hi all,

Are those charts showing PH/KH for CO2 something that I should not pay too much attention to then?

Not really, you can only use them when you adding CO2. Often you get people say something along the lines of :

..... I had a pH7 and 11 dKH and therefore I had 33ppm of CO2.........

Which is definitely wrong if you <"aren't actually adding CO2">.

So if the DC is lime green it will always be in the range of around 30ppm CO2 no matter what my KH

It will.

We still don't know if "30ppm CO2" really is 30 ppm CO2, because it is based <"upon the assumption"> that there is about <"3ppm CO2 in water">.

We also think the reason why dKH is irrelevant (when you have more than about ~4dKH) is because <"pH is a log10 scale"> (you need to read from this post until the end of the thread).

cheers Darrel

 

[Luvlyjub]

Thanks for all the good advice and now much clearer.

As mentioned I am testing before I fully set-up to ensure I have a good understanding to maintain livestock as well as the plants.

I have always used tap water in my tanks but for this new set-up with CO2 I am now going with 50/50 RO to reduce TDS (for shrimp as currently over 500) and I hope will reduce the PH swing that was 1.35 in testing and therefore achieve what seems the accepted 1 drop in PH?

 

[ceg4048]

Thanks for all the good advice and now much clearer.

As mentioned I am testing before I fully set-up to ensure I have a good understanding to maintain livestock as well as the plants.

I have always used tap water in my tanks but for this new set-up with CO2 I am now going with 50/50 RO to reduce TDS (for shrimp as currently over 500) and I hope will reduce the PH swing that was 1.35 in testing and therefore achieve what seems the accepted 1 drop in PH?

When we add CO2 we are not concerned about limiting pH swing. Too many hobbyists worry about pH without fully understanding what this measurement actually is and they waste a lot of energy trying to control it. An insight into pH is provided the post=> Unlimited nutrients using E.I.

The reason a 1 pH drop is accepted is because this typically indicates the the level of CO2 being injected is at or near 30ppm, which itself is an arbitrary value that most agree is enough for good plant growth, but which is typically below the toxic threshold for most fauna. Depending on other conditions of your tank or depending on your goals a greater drop or a lesser drop can be used, which means more CO2 or less CO2 can be used. 30ppm should not be misconstrued as some kind of plant Nirvana.

Cheers,