KH pH and CO2

**AquaObsession** · 11th Mar 2006, 21:08

Hi

Just something that will sound silly to all of you..

My KH is 4 (measured from serra kh kit just bought)
MY ph is 7-7.1 from PH pen
this means my Co2ppm is around 10. from the calculator

some of my plants are pearling..very low though,, my tank has about 3.5 wpg... no algae issue so far... but i want more pearling, and i know i need to increase Co2 (also to prevent algae from coming)

should i increase the bps? then measure PH/KH?

How to get it to 30ppm.. I am pumping now (and as usual since I shifted to EI) around 4-5 bps, using reactor method...

Should I just lower PH using some acid?? or increase KH using some buffer??

Maybe something that i missed out when reading on Co2 ppm..

anyone can help?!

**|squee|** · 11th Mar 2006, 21:33

No you should not lower the pH nor tamper with the kH. Leave the kH alone (unless it's very very low like 1 degree), and lower the pH using CO2 only.

PeterGwee will take you on the finer points of CO2 increment.

**AquaObsession** · 11th Mar 2006, 21:49

Okie,,,,so i only slowly increase level of Co2 until i get a ph and KH reading which give me 30 ppm....

**PeterGwee** · 11th Mar 2006, 22:11

pH/KH are just measurements used to determine CO2 from an acid/buffer relationship. If you want more CO2, you just need to add more and not some acid. Plants want the CO2 and not stuff that depress the pH.

Regards
Peter Gwee

**AquaObsession** · 11th Mar 2006, 22:33

One thing that i worry about is...... i am adding Co2 like 5-6-7 bps...and my ph and Kh are 7.0-7.1 and 4 respectively.... and i am using reactor method... and my plants pearl at lot only at end of the day..after hours of being exposed to Co2... while increasing Co2 to 5-6-7 bps, my fishes are fine..none gasping at the top..at all.. in first 3-4 hours with lighting and Co2, plants peal only slightly.... hmm dun get the impression that I am want at all costs heavy pearling..rather my question now is...is it normal to add Co2 to tank at rate of 5-6-7 bps? I feel it;s quite weird for a 2 feet rite?

**PeterGwee** · 11th Mar 2006, 22:41

Unless you are blowing off CO2 rapidly through surface agitation, I would question the measurements.

Regards
Peter Gwee

**AquaObsession** · 11th Mar 2006, 23:44

Hmm, no, only a gentle surface movement....

at least if my ph or kh is wrong in measurement, i suspect my PH pen for that......but at least i should see my fish gasping at the top....hmm, i suspect my CO2 cylinder filled with low quality Co2

this is the only explanation I can find...

anyway, i just did water change today.... but from past week, similar as well,,, i blew 4-5 bps per second, and plants only pearl at end of day.....

anyway, i will monitor and report...

**PeterGwee** · 12th Mar 2006, 00:51

Does your reactor get fill up with an air-pocket (it should as the day goes by)? If not, you likely have a leak somewhere especially with reactor methods where there is a certain amount of back-pressure. 4-5bps is really too much...

Regards
Peter Gwee

**AquaObsession** · 12th Mar 2006, 10:40

When we are in the first few hours, usually most of the Co2 get diffused very fast...... even when i open my co to 10++ bps just to try to force some more co2 in for a few second as i was testing yesterday, the reactor get filled with Co2 air, then diffused very fast (if this is done in first few hours)...

at end of the day however, seems there is some build up of Co2 in the reactor...about 1/10 or 1/20 of it... and when lights are off, usually take 1-1.5 hrs to clear out everything...

I guess it is normal, and there is no leak...

Wat i was testing also yesterday.,..how long will it take to diffuse 3/4 of reactor full with Co2, given that most of the Co2 is trapped inside the reactor (instead of going out of reactor)...well, amazing, it took about 2 min..... and this is with minimal loss of undiffused Co2 that leak out of the reactor... (test was done within 3 hours when lights were on)

I'll post a pic of the tank with reactor...

does not seem that my fish will be gasping if i increase to 6+ bps...

may be i should switch to my other Co2 cylinder and test it... coz i suspect my current cylinder does not contain Co2 per say..or a very low quality one...

i switched to my an old cylinder, and set bps to 3. will see how.

**AquaObsession** · 12th Mar 2006, 15:46

here are some pic of my tank...it's posted as well in aquascaping forum...

the reactor is just normal type..internal...hence dunno how or where Co2 can leak...

**Ibn** · 12th Mar 2006, 16:47

Can you verify the validity of the new test kit (KH kit)?

Also, is your co2 on all day or just only on during part of the day?

**StanChung** · 12th Mar 2006, 21:17

culd the prob be the reactor outlet pointing upwards?

**AquaObsession** · 12th Mar 2006, 21:40

Hi

No the problem I guess is not with the reactor pointing up...

Hmm, initially, about a week ago, when I did this setup, I had to tie the Bogwood to a big piece of stone. I am thinking that the problem might be with it...as in the stone might be increasing Ph or doing something to HK,,i dunno ..not sure when i talk abt these...

So, I spent some time and took it out of the tank.. sadly the wood still does not sink.,..so I put another type of stone on it to sink it..

The scape has not been disturbed much, I acted with due care...

I recorded PH after 4 hrs, it gave me a reading of 6.8-6.9 I guess the problem was with the stone...

But the issue of Co2 is till not solved?? Very weird that when I put 5-6 bps, no gasping of fish...hmm,,,

to answer the question of IBN,yes, Co2 is on for whole day... from 1100-2100

Over the next few days, I will monitor the Ph level ..

btw, my KH measure is 3...initially was 4.. so i guess the range is unchanged (3-4)

Fishes are active, shrimps are active..loaches are fine..sometimes (most of the time) hiding..otto are fine...plants pearling low though, even at end of day...but i assume it was because of the water change this afternoon again...(because I took out the stone, I did a water change as well 50%)

Will report more on PH and KH over the week...

how i get lots of pearling with my last setup was that, i used 2*55watts for a few hours..say 2 hrs.. then when i switched one off, the plants still pearl with 1*55... as if they need extra lights to wake up and start photosynthesis..if i start with 1*55, pearling only occurs at end of day... Anyone can comment if there is such a wake up issue... my tank is 60*30*45cm (l*W*H)

**AquaObsession** · 14th Mar 2006, 11:49

Will some new measurements tonite... I did some changes to the tank again to make it a permanent tank..

**bossteck** · 14th Mar 2006, 19:35

Hi,

You can't adjust the co2 level by adjusting your ph or kh, so don't try anything in this direction or you might end up hurting your fishes.

My first suspicion is, you have a leak somewhere, check your tubing, are you using any check valve? co2 may be escaping at the joints of your air tube.

Pearling effect is the result of saturation of dissolved gases in your water column, combined with high level of photosynthesis, so probably the level of dissolved gases in your tank isn't enough, this usually takes time. Your plants are probably photosynthesising throughout the photoperiod, it's just that you need to give the water column time to get saturated first.

Incidently, were you having the same species of plants in your old setup? Tank same size?

**AquaObsession** · 14th Mar 2006, 22:34

HI,,, maybe you are right about the saturation and stuff...no, not the same species of plants..and also, I just did water change...but tank size is the same...

I have made changes to the tank again, since this is now going to be my permanent tank... Will monitor and report Co2 and KH... Yeps, I get the point not to make any changes to PH by adding acid etc...

**AquaObsession** · 17th Mar 2006, 22:09

Hi,,,

more precise measurement..the intial measurement error was because of non calibrated ph pen.

PH (when Co2 is off at night) 6.5
PH with Co2 during day, 6-6.1

KH with sera test kit : 1

this gives me a ppm of 23-30

but plants low pearling... i suspect the low ph comes from the introduction of ada amazonia soil.

what should i do now if let's say i want a ph around 6.5 and Kh around 3-4 to get 30ppm such that the PH is right for my fishes and plants as well...

if i introduce Co2 at rate of 1-2 bps, my ph can drop from 6.5 to 6 in one day...( i assume this is because my kh is low, so the buffering capacity is low)_

but you guys told me (previous posts) not to touch PH or KH, just play with Co2 bps to achieve 30-35 ppm....

Comments are welcome...

**valice** · 18th Mar 2006, 11:23

The pH and kH readings after adding ADA soil cannot be used for CO2 calculation any more as it has been changed due to the pumice in the soil... And not due to your CO2 injection anymore...

So you can only use your plants and fishes as guide to the amount of CO2 you can add into your tank...