I am doing it...

[Bill M.]

I am making this DIY CO2.. [Only Registered Users Can See Links.]

I will buy me a kH test kit on friday, when I get paid...

Ill follow up on how it went

[tropfish]

good luck!

[Zerileous]

cool man, have fun.

Some more links you might want to look over before you do it:
[Only Registered Users Can See Links.]
[Only Registered Users Can See Links.]

Also, I find that if you drill the hole small enough you wont need any sealant for the air line. You just have to cut the line at an angle and then pull it through with pliers. Also make sure you use at east silicone air line because the other stuff will be degrated by the CO2 (though there is something even better than silicone, I just use the silicone).

[Bill M.]

So I just got home, its 11 pm, and checked out my CO2..... its going great at about 50-60 bubbles a minute......
but.... I checked my pH, and it has dropped from 7.8 to 6, from right before I added the CO2. Isn't it supposed to only drop 1??? I turned on my airstone, just for the night to prevent my fish from suffering, but during the day the bubbles are off.... I am confused.. someone help meh!

[Drumachine09]

...Thats odd.

*turns on giant chrona/HH shaped spotlight and aims it toward the sky*

[Zerileous]

oh, it can drop more than that. The 1pH thing is a little different. If you take a cup of water out and let it sit for 24 hrs, then it should be 1pH higher (or less).

You measure dissolved CO2 by comparing pH to kH. There is a chart on [Only Registered Users Can See Links.]. Basically CO2 in the water produces carbonic acid. This is what cuases the pH to drop. The ammount it drops depends on the buffering in the water, or kH. So if you have low kH, it will allow a larger pH swing from the same ammt of carbonic acid. This is why we can't go on just pH.

It can be dangerous to run CO2 with a low kH for this reason, so if you have less than 3 degrees kH you should boost it with baking soda every water change. I doubt you have this problem but if you do I can point you to a webpage with the proper doses.

I run an airstone with my DIY CO2 at night. I have it on a timer to start when the lights go off, and turn off 1 hr before the lights.

let me know if you have more questions or need more clarification

ps. your CO2 output will decrease dramatically over the next few days, which is normal for a DIY system.

edit pps. i need to try that recipe, 40 bubbles per min is really good!

[zackish]

Ok, coming straight from what chrona told me..........
1. Don't turn off your Co2 at night, just have something to break the surface.
2. are you running your DIY Co2 with an airstone or just the end of a bare hose? If you are running it with an airstone take the stone off and see how many bubbles you make then. In his tank he runs about 1 bubble per second. In my tank I am getting about 1 bubble about every 4 seconds, which I plan to adjust.
3. The only way to accurately determine your Co2 level is by a dropper kit. The water turns a certain color and lets you know if your ppm is just right, not enough or to much. Chrona said these can be found for cheap on ebay.

This is just what I have gathered from conversations me and him have had.

[Algenco]

Here is a link for a good drop checker $10 shipped with reagent.
The guy that makes them has a seriously ill son (heart) and needs money for medical bills

[Only Registered Users Can See Links.]

[hungryhound]

Ok, coming straight from what chrona told me..........
1. Don't turn off your Co2 at night, just have something to break the surface.

If you turn it off or close the system you have just created a bomb.


2. are you running your DIY Co2 with an airstone or just the end of a bare hose? If you are running it with an airstone take the stone off and see how many bubbles you make then. In his tank he runs about 1 bubble per second. In my tank I am getting about 1 bubble about every 4 seconds, which I plan to adjust.

3. The only way to accurately determine your Co2 level is by a dropper kit. The water turns a certain color and lets you know if your ppm is just right, not enough or to much. Chrona said these can be found for cheap on ebay.

This is just what I have gathered from conversations me and him have had.[/QUOTE]

True but the chart is not horrible either.


So I just got home, its 11 pm, and checked out my CO2..... its going great at about 50-60 bubbles a minute......

50 to 60 bubbles per minute is only 1bps which seems about right.

but.... I checked my pH, and it has dropped from 7.8 to 6, from right before I added the CO2.

That seems like a fairly large drop and something does not seem right. It may be entirely possible that this is correct, but I am very suspect of this.

as Zerilous said I would do the cup of water method. Take a sample of water and let it sit for 24 hours to degass the sample and then retake the reading. Ideally this should be at 1 degree change.


Isn't it supposed to only drop 1??? I turned on my airstone, just for the night to prevent my fish from suffering, but during the day the bubbles are off.... I am confused.. someone help meh!

yes it is normally only supposed to drop 1 degree, but there are exceptions to the rule and we will need to know your KH.

looking at the chart. at this link

chart at bottom of page ([Only Registered Users Can See Links.])


it is possible that you have a very low KH and your co2 content is only 15.

It is impossible to tell without either a drop checker or a KH reading.

However. Are your fish swimming at the surface trying to get oxygen. If not I would leave it for the time being until you get a KH probe.

[Bill M.]

Hye HH....

Yea I am headed to petsmart in an hour or so to buy a kH test kit, a drop kind... just eating lunch and taking a shower first :) *just got home from work* With the cup test, cant I just run an air stone in the sample so I dont have to wait 24 hours??? My fish arnt gasping tho, so that is good...

[hungryhound]

Hye HH....

Yea I am headed to petsmart in an hour or so to buy a kH test kit, a drop kind... just eating lunch and taking a shower first :) *just got home from work* With the cup test, cant I just run an air stone in the sample so I dont have to wait 24 hours??? My fish arnt gasping tho, so that is good...

The problem with running the air stone in the sample is how long do you run it. How do you know that you have gotten all of the CO2 out of solution. Like most things in this hobby patience is required,

You are more than welcome to try it, but i am not sure how accurate your answer will be.

[Zerileous]

drop checkers are nice and all, but it is my humble opinion that their importance has been overstated. A drop checker just uses the same stuff in your pH test kit mixed into a 5dkH reference solution. The color changing just reflects pH due to dissolved CO2 in the reference solution (and thus the tank). The advantage of a drop checker is that it gives you an instant read to estimate your CO2 levels (low, just right, toxic). The disadvantage is that you loose some level of accuracy compared to hand testing both kH and pH methinks. Instead of reading a chart to figure out the exact ppm, you just know that its bad, good, or worse. I think they work better with a controlled system where CO2 level is controlled by a valve, rather than maximum efficiency of a DIY bottle.

[hungryhound]

drop checkers are nice and all, but it is my humble opinion that their importance has been overstated. A drop checker just uses the same stuff in your pH test kit mixed into a 5dkH reference solution. The color changing just reflects pH due to dissolved CO2 in the reference solution (and thus the tank). The advantage of a drop checker is that it gives you an instant read to estimate your CO2 levels (low, just right, toxic). The disadvantage is that you loose some level of accuracy compared to hand testing both kH and pH methinks. Instead of reading a chart to figure out the exact ppm, you just know that its bad, good, or worse. I think they work better with a controlled system where CO2 level is controlled by a valve, rather than maximum efficiency of a DIY bottle.

very well and eloquently stated. I too would not purchase one unless I had a pressurized system.

[Bill M.]

Well I just checked my kH and it is 20 mg/l. My pH is 6.4....Does that sound right?

[Bill M.]

Ok.. so I found on a nutrafin board that you take the mg/l and divide it by 17.86, which will turn it into ppm... So i did this and I have 1.1 ppm kH

[Willyleigh]

Ok.. so I found on a nutrafin board that you take the mg/l and divide it by 17.86, which will turn it into ppm... So i did this and I have 1.1 ppm kH

1mg/l is the same as ppm, one mg is 1000th of a gram, one gram is 1000th of a liter (by weight)

[Zerileous]

that sounds really really low. I think we need to confirm this. Is your test one of the titration type kits from API or something else? Is there any way to get a reading directly in degrees kH?

I am getting confused by all these units of measurements myself; ppm meq/L mg/L dkH AGGGGH! Okay just kidding, but we do need to be 100% perecent sure we have the proper values converted to the proper units before we make any CO2 calculations or dose baking soda.

I have read that ]
To convert from mg/l of alkalinity to meq/l you have to divide
the alkalinity by 50 to get meq/liter, then you multiply by 2.8 to get
degrees. Or just divide by 17.9 - its the same thing.


So according to this quote, you have 1.1dkH and thus 11.9ppm dissolved CO2 (which seems reasonable for a DIY system) Lets not jump to any conclusions yet though. Ill keep digging.


Edit:
This page ([Only Registered Users Can See Links.]) contians a good description. Though its written in the context of salt water, its a really good general description of kH.

The alkalinity of water ([Only Registered Users Can See Links.]) is measured in either dKH, meq/L, or mg/l. (If it is wished to convert dKH to mg/l, simply multiply dKH by 17.9.)
Thus me may allow that 1dkH = 17.9 mg/l
So by this we may take 20 mg/l over 17.9 mg/l = 1.1 dkH

According to this conversion:
A. you have about 12ppm dissolved CO2 (still well within safe levels for the fish) using this chart ([Only Registered Users Can See Links.])

B. Your kH is low enough that running CO2 could cause pH swings that are dangrous to your fish.
]
A pH anywhere in the 6.4-8.5 range is fine. A general hardness, gH, of 3-15 degrees and a carbonate hardness, kH, of 3-12 is fine. If your water is very soft and you are using CO2 injection you want to be sure and add something to get your kH up to at least 3 degrees to prevent large pH swings. If your gH is very low then you may need to provide your plants with calcium and magnesium.
C. We need to boost the kH in the tank. One way to do this is by adding baking soda
]
To raise kH use baking soda. One teaspoon will increase the kH of 50 liters of water (13 gallons) by 4 degrees (68 ppm).
To err on the safe side, lets increase kH by 3dkH to achieve a total kH of 4.1dkH.

Let me go work on the conversions for this...It might take a while since I have not had chemestry for a few years.

EDIT2:
so if we wanted to raise only 3dkH in 13 gallons:

1tsp/4dkH = xtsp/3dkH
4x dkH*tsp = 3 dkH*tsp
divide by 4 dkH
x tsp = .75 tsp to raise 3dkH in 13 gallons.

And if we wanted to do the same in 30 gallons:

.75tsp/13g = xtsp/30g
22.5 tsp*g = 13x tsp*g
divide by 13 g
x tsp = 1.75 tsp.

I would recomend you check my math before dosing just to be sure. I would also recomend measuring the kH straight from the tap and see if thats the same or different as you will need to dose water changes too.

ALTERNATELY: you can ignore this advice and not mess with baking soda. Chances are things will be okay but you would have to monitor pH carefully at all hours of the day for the first few days. There is more risk for the fish this way, but less trouble. Your call.

WARNING: I have never had to dose baking soda to increase kH before and cannot guarantee the effectiveness of this method. That being said the website I used is very reliable. Regardless, I would test some water outside of the fishtank with baking soda to see what happens first.

[Bill M.]

OMG. DUDE... ure like, a math wiz....

ill do another test with tap and tank water.. I am not sure if I like this kit cause here are the instructions:

"1) Take a sample of the water to be tested in the pipette. Use it to fill a clean test tube to the 5 ml line.
2) Add one drop of kH reagent into the test tybe. Insert cap and shake well to mix. A blue color should result. Attention! Awlays use cap, avoid skin contact. If the color of the mixture changed to yellow after adding the drop, the carbonate hardness is velow 10 mg/l as CaCO3.
3) Continue to add a drop at a time and shake after each addition. Count drops and stop adding them when color changes from blue to a yellow/lime color. For best results, hold test tube flat against the paper and read with a light source behind you.
4) Multiply the total number of drops by 10 to determine the general hardness in mg/l as calcium carbonate (CaCO3)

I did this, and not including the first drop, added 2 drops before a yellow tint was visible, so according to that, I have 2o ppm hardness....

[Bill M.]

Here are the pix of my test kit... they go in order posted... each pic is one more drop than the previous....

[hungryhound]

a KH of one is low, but it makes sense with your pH drop and your fish still being fine.

According to the chart you are sitting at 30 ppm. Right where you should be.

I would have been more confused if your KH was 6 or higher.

[Bill M.]

So should I not tamper with the kH? Zerileous and I have been talking and came up with if I add 1.75 tsp of baking soda, the kH will rise bout 3 degrees, and prevent subsecuent pH swings......waht do you think HH?

[hungryhound]

So should I not tamper with the kH? Zerileous and I have been talking and came up with if I add 1.75 tsp of baking soda, the kH will rise bout 3 degrees, and prevent subsecuent pH swings......waht do you think HH?

Adding baking soda to increase KH is fine. Most people like to have thier KH at or around 4.

I believe Chrona did this to his tank for a while.