Can this be right?

[JDogg]

First how long would you trust a AP master kit PH test? my kit is ~ 1 year old, should i pick up a new one?

if it is correct then after running diy co2 on my 75 for 24 hours my ph has droped .6-.8 :?

PH = 7.4-7.2 (was a good solid 8.0)
KH = 250.6 ppm

according to THIS PAGE my CO2 is in the good level.... 26.56 ppm

Thoughts... Suggestions....

thanks!

 

[Purrbox]

Depending on the number of CO2 generators and the efficiency of your reactor, you could get that good of a result. More details about your CO2 Setup would help us figure out whether it's more likely to be a problem with the test kit or accurate results.

 

[JDogg]

Depending on the number of CO2 generators and the efficiency of your reactor, you could get that good of a result. More details about your CO2 Setup would help us figure out whether it's more likely to be a problem with the test kit or accurate results.

basic DIY setup

two 2 liter soda bottles - 6 cups water, 2 cups sugar and 1/4 tsp activated yeast in each bottle.

bottles are connected with a T connector, run through a check valve and into a bell diffusor made from the top of a 20 oz soda bottle...

 

[Purrbox]

Under those circumstances, I find the results highly doubtful. I would suspect a bad test kit, testing error, or a buffer that is throwing of the CO2 calculation.

 

[JDogg]

Under those circumstances, I find the results highly doubtful. I would suspect a bad test kit, testing error, or a buffer that is throwing of the CO2 calculation.

i can pick up a new test kit tomorrow and re-test...

any ideas of what might be buffering it?

i have three pieces of driftwood, but they have not affected my ph, had then ~ 6 months...

 

[7Enigma]

When was the pH a good solid 8? Right in the morning when the lights came on? Or during the middle of the day after a couple of hours.

It's really important that you measure the same time each day since respiration of both plants and animals will change depending on their activity.

Also make sure your pulling from the same place each time. I like to use a pipet and pull water from the middle of the tank. There is less pH variation from CO2 gas-off here than at the surface where most people take their water samples.

I do agree however that its highly unlikely in the size tank you have with a passive diffusion that you are getting that high tank levels...

I think you are the perfect candidate for pressurized, but at the minimum I think a quad setup would be needed to have acceptable levels (>15ppm).

 

[JDogg]

When was the pH a good solid 8? Right in the morning when the lights came on? Or during the middle of the day after a couple of hours.

It's really important that you measure the same time each day since respiration of both plants and animals will change depending on their activity.

Also make sure your pulling from the same place each time. I like to use a pipet and pull water from the middle of the tank. There is less pH variation from CO2 gas-off here than at the surface where most people take their water samples.

I do agree however that its highly unlikely in the size tank you have with a passive diffusion that you are getting that high tank levels...

I think you are the perfect candidate for pressurized, but at the minimum I think a quad setup would be needed to have acceptable levels (>15ppm).

i take the ph reading about the same time every time (evening around 7-8 ) i do take it from the surface though. i know i would get better CO2 from pressurized, but being only lightly planted i have a hard time justifying the expense... i am not to the "planted tank with fish accent" stage yet i could easily add a couple more bottles.
i also have one of THESE on order, so hopefully i will get better diffusion then just a bell diffusor. got an hour more of work, then i can stop and pick up a new test kit, i will post tonights test results...

 

[mr funktastic]

that reactor will not be much better than the bell. i have one in my tank and by itself it isnt all that great. even after travelling the ladder there is still a bubble that escapes from the top that does not get diffused. i fixed this problem by placing the ladder underneath my filter intake. this way the escaping bubble gets sucked up and diffused completly. it also doesnt make near as much noise becasue the bubble gets soo much smaller by the time it gets sucked up. i get high results in my 20 gal with 2 2 litre bottles.

 

[7Enigma]

that reactor will not be much better than the bell. i have one in my tank and by itself it isnt all that great. even after travelling the ladder there is still a bubble that escapes from the top that does not get diffused. i fixed this problem by placing the ladder underneath my filter intake. this way the escaping bubble gets sucked up and diffused completly. it also doesnt make near as much noise becasue the bubble gets soo much smaller by the time it gets sucked up. i get high results in my 20 gal with 2 2 litre bottles.

As I understand it, the bubble itself does not need to disappear in order to fully have the CO2 dissolved. And by fully I mean to the same level of CO2 as the tank water. In a saturated system oxygen and other gases will replace the air in the bubble as it is rising up the ladder (or just bubbling in a tank but to a lesser extent). Yes the bubble will get smaller as the CO2 quickly dissolves in the water, but then you should see very little difference in bubble size.

There was a HUGE controversial thread on another forum awhile ago where they went through the chemistry/physics of partial pressure and solubilities. Since water has a theoretical solubility of >1500ppm CO2, it will never reach the point at which it will not diffuse into the water. Once it reaches the surface that's a different story (~1-3ppm CO2 will equilibrate in the water without injecting CO2).

I believe this thread was relating to injecting a CO2 mist into the water as opposed to the more common methods.....

 

[mr funktastic]

well i got very clear differences in co2 once i set up the ladder under my filter. i dont have numbers to back that up since i dont have a kh test kit but i have visual differences. and pearling to back it up. the bubble goes from about 5 mm to about 2 by the time it leaves the ladder so there is a significant change in the size of it.

 

[JDogg]

ok new test kit gives me a ph of 7.6-7.8

 

[Purrbox]

That's 7-11ppm CO2, and much more along the lines of what I'd expect to see.

 

[JDogg]

That's 7-11ppm CO2, and much more along the lines of what I'd expect to see.

so i should probably add another two bottles...right now my BBA is Pearling :? ...but so is my amazon sword (very little)... so kind of mixed results

 

[Purrbox]

While two more bottles will get you closer, I'm guessing that you need more like to 4 gallon bottles unless you get a more efficient CO2 diffuser.

 

[JDogg]

While two more bottles will get you closer, I'm guessing that you need more like to 4 gallon bottles unless you get a more efficient CO2 diffuser.

what would you suggest as a more effective diffusor? i have a ladder tip diffusor on order

 

[Purrbox]

There are two types of diffuser, passive and powered. Powered diffusers are much more effective than passive diffuser on the whole. Both the diffuser that you are currently using and the ladder on order are Passive Diffusers. You best bet would be a powered reactor like this or this. These may not be the best prices, but are meant to show the to basic designs. Both can be bought retail or made DIY.

 

[mr funktastic]

a DIY reacotr would be best and cheapest. i know lonewolf just made one using a recent design that was shown here ... just gotta find the link.

 

[rkilling1]

what do you guys think of this:

http://cgi.ebay.com/Bio-Chamber-BLO...4QQihZ009QQcategoryZ46310QQrdZ1QQcmdZViewItem

?????

17 bucks total, how does that sound? that is the same reator that everyone has been building on here correct?

 

[Lonewolfblue]

Looks very similar, yes. wish I hadn't ordered my reactor yet, lol. Ah well....

 

[7Enigma]

There are two types of diffuser, passive and powered. Powered diffusers are much more effective than passive diffuser on the whole. Both the diffuser that you are currently using and the ladder on order are Passive Diffusers. You best bet would be a powered reactor like this or this. These may not be the best prices, but are meant to show the to basic designs. Both can be bought retail or made DIY.

Wow that 2nd link is a rediculous price for such a low-tech item. I can't believe they can sell something that expensive...