PH drop and CO2 calculation

Hi everyone,
I need your help on this. I've been battling with BGA on my 70 Galon tank for the last 4 months and plants are not growing as expected (I'm dosing almost 2 TBS of KNO3, increased current..nothing seem to help); finally I got an American Marine Pinpoint PH meter to check the tank's CO2. I took the PH readings and I hope you can help me to determine where I'm standing.

Before CO2 comes on, ph is about 6.3, also I took water from the aquarium in a cup, agitated it and after a couple of minutes PH rises to 6.6. After an hour of CO2 injection, ph drops to 5.4 and then remains stable between 5.20-5.25 after an hour and a half. So let's say I'm having a 1.4 PH drop after 1.5 hours. Because KH is unmeasurable in my case, (less than 1°dKH), how can I know if levels are correct?

I'm using a DIY wet dry filter and there's no splash in the overflow. CO2 is injected via DIY NW and 4x20" filter housing as reactor. CO2 enriched water is taken by the main pump.

Thanks for your help.

Light is arround 90umol in the bottom. I dose the full EI (but increased KNO3 battling BGA)...KH2PO4, GH Booster and Fe/micros from CSM+B, Fe Gluconate and EDTA. I even changed my KNO3 supplier 2 times, didn't help.

I rise GH a couple of degrees after a water change via Barr's GH Booster. KH is less than 0.5 degrees according to Sera and Tetra KH test kits, that's why I'm having problems measuring CO2.
I'm dosing 2 TBS of KNO3, 1/4TSP KH2PO4 and I aim to 0.4ppm of Fe each dose. Nothing special I think, except for the KNO3.

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I rise GH a couple of degrees after a water change via Barr's GH Booster. KH is less than 0.5 degrees according to Sera and Tetra KH test kits, that's why I'm having problems measuring CO2.
I'm dosing 2 TBS of KNO3, 1/4TSP KH2PO4 and I aim to 0.4ppm of Fe each dose. Nothing special I think, except for the KNO3.

Thanks Solcielo, 0.4 of Fe calculated from CSM+B.
Here are some photos.











I recently cleaned everything, but it takes about 2 days to have everything covered with BGA. I tried the BO method, EM dosing...

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Thanks Solcielo, 0.4 of Fe calculated from CSM+B.
Here are some photos.











I recently cleaned everything, but it takes about 2 days to have everything covered with BGA. I tried the BO method, EM dosing...

Thanks Solcielo,
There was more plant mass in there, but I took a couple of species out thinking about CO2 competition. I'll increase CSM+B dosing and see if it helps.

What about CO2?
What's your opinion on BGA?

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Thanks Solcielo,
There was more plant mass in there, but I took a couple of species out thinking about CO2 competition. I'll increase CSM+B dosing and see if it helps.

What about CO2?
What's your opinion on BGA?

Hi, Thanks for your help Solcielo
I redid my micros mixture and started adding it yesterday as follows.
3TSP of CSM+B
1TSP of Iron Chelate bought from greenleafaquariums.com
Since I couldn't get Fe Gluconate and I have Fluorish Iron locally, I added 30ml of it to get the same concentration Tom suggests in his mixture (arround 304ppm).
20ml of excell
Everything disolved in 1L of water.
I'm adding 30ml daily.

I was adding almost 140ml of CO2/min. I reduced it to 60ml/min, seems that efficiency was greatly affected as volume of CO2 increased.
I did the sera KH test to get readings of 0.25dKH, and the aquarium KH was somewhere between 0.75 and 1 dKH. I used Alkaline Buffer to rise it to 1.5dKH. The aquarium PH is 5.54 now after 3 hours of CO2 injection. Agitated water for 2 minutes and the reading was 7.1.

I'm still having a 1.46 PH drop even with the reduced volume of CO2, but according to the KH/PH cart with a KH of 1.5 and a PH of 5.54 I have 115ppm of CO2 (nuts), Should I assume that the only Carbonate Hardness is the increase of KH that I did with the Alkaline Buffer?

Regards

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Hi, Thanks for your help Solcielo
I redid my micros mixture and started adding it yesterday as follows.
3TSP of CSM+B
1TSP of Iron Chelate bought from greenleafaquariums.com
Since I couldn't get Fe Gluconate and I have Fluorish Iron locally, I added 30ml of it to get the same concentration Tom suggests in his mixture (arround 304ppm).
20ml of excell
Everything disolved in 1L of water.
I'm adding 30ml daily.

I was adding almost 140ml of CO2/min. I reduced it to 60ml/min, seems that efficiency was greatly affected as volume of CO2 increased.
I did the sera KH test to get readings of 0.25dKH, and the aquarium KH was somewhere between 0.75 and 1 dKH. I used Alkaline Buffer to rise it to 1.5dKH. The aquarium PH is 5.54 now after 3 hours of CO2 injection. Agitated water for 2 minutes and the reading was 7.1.

I'm still having a 1.46 PH drop even with the reduced volume of CO2, but according to the KH/PH cart with a KH of 1.5 and a PH of 5.54 I have 115ppm of CO2 (nuts), Should I assume that the only Carbonate Hardness is the increase of KH that I did with the Alkaline Buffer?

Regards

The tank has been running for about a year, I'm doing 60% WC every fourth day.
This is what rota.la calculator shows about my micros dose per day

B 0.01
Cu 0.00
Fe 0.08 + 0.07ppm of Fe from FE gluconate + 0.03ppm of FE from Iron Chelate
Mg 0.02
Mn 0.02
Mo 0.00
Zn 0.00
dGH 0.00

Seems a bit low according to this quote from Tom Barr:

B 0.17
Cu 0.01
Fe 0.94
Mg 0.20
Mn 0.27

This is about what I dose for my tanks per dose, 3-4x a week.

~1ppm is a typical dose for Fe.

Not 0.1ppm.

am I missing something?

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The tank has been running for about a year, I'm doing 60% WC every fourth day.
This is what rota.la calculator shows about my micros dose per day

B 0.01
Cu 0.00
Fe 0.08 + 0.07ppm of Fe from FE gluconate + 0.03ppm of FE from Iron Chelate
Mg 0.02
Mn 0.02
Mo 0.00
Zn 0.00
dGH 0.00

Seems a bit low according to this quote from Tom Barr:

B 0.17
Cu 0.01
Fe 0.94
Mg 0.20
Mn 0.27

This is about what I dose for my tanks per dose, 3-4x a week.

~1ppm is a typical dose for Fe.

Not 0.1ppm.

am I missing something?

Hi,
Solcielo, I wrote to Tom about the information I've found and posted before. He agreed with what you've been saying.
I reduced the Micros dosing to 10ml/day
The preparation is as follows: 3TSP of CSM+b + 1TSP Fe gluconate + 1TSP Iron Chelate DPTA in 1L of water.
According to rota.la calculator, I'm adding:

B 0.003
Cu 0.000
Fe 0.028 + 0.014 from DTPA + 0.01 from Fe Gluconate TOTAL FE: 0.052ppm
Mg 0.006
Mn 0.008
Mo 0.000
Zn 0.002
dGH 0.001

What do you think?

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Hi,
Solcielo, I wrote to Tom about the information I've found and posted before. He agreed with what you've been saying.
I reduced the Micros dosing to 10ml/day
The preparation is as follows: 3TSP of CSM+b + 1TSP Fe gluconate + 1TSP Iron Chelate DPTA in 1L of water.
According to rota.la calculator, I'm adding:

B 0.003
Cu 0.000
Fe 0.028 + 0.014 from DTPA + 0.01 from Fe Gluconate TOTAL FE: 0.052ppm
Mg 0.006
Mn 0.008
Mo 0.000
Zn 0.002
dGH 0.001

What do you think?

I can dose the CSM+B dry alone and see if it helps, but, ¿how much is a recomended dose?
I'm a bit confused, 0.1ppm of Fe is what I've read, Tom said in other forums that 1ppm, but my calculations doesn't match.
Thanks

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I can dose the CSM+B dry alone and see if it helps, but, ¿how much is a recomended dose?
I'm a bit confused, 0.1ppm of Fe is what I've read, Tom said in other forums that 1ppm, but my calculations doesn't match.
Thanks

Hi everyone.
After a week, some things improved.
Good news: BGA is almost gone. I can't tell if any specific change made it, but I'm sure that it has to do with plant's health. Ussually after cleaning, it took about a day to BGA to re-grow everywhere; now, there are little patches in the glass which I can assume to be normal.
Bad news: Even with the plants growing a little better, there's something confusing about my CO2 levels:

Here are some readings after 5 hours of CO2:
Aquarium water PH: 5.23
Agitated aquarium water PH after 5 minutes: 7.03
KH from Sera KH test: 9-10 drops in 60ml (0.083dKH accuracy)
KH from Tetra KH test kit: 8-9 drops in 60ml (0.083dKH accuracy)

KH is about 0.74 degrees.

Fish are stressed, but I think that if I had 130ppm of CO2 there wouldn't be any, and I would have more money from selling plants

Questions:
¿Can such a low KH cause problems on PH readings? (I'm using an American Marine Pinpoint PH meter)
¿Is it wise to increase KH to take better/more accurate CO2 readings?
¿Can that be affecting plant's growth?

Thanks for your help.

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Hi everyone.
After a week, some things improved.
Good news: BGA is almost gone. I can't tell if any specific change made it, but I'm sure that it has to do with plant's health. Ussually after cleaning, it took about a day to BGA to re-grow everywhere; now, there are little patches in the glass which I can assume to be normal.
Bad news: Even with the plants growing a little better, there's something confusing about my CO2 levels:

Here are some readings after 5 hours of CO2:
Aquarium water PH: 5.23
Agitated aquarium water PH after 5 minutes: 7.03
KH from Sera KH test: 9-10 drops in 60ml (0.083dKH accuracy)
KH from Tetra KH test kit: 8-9 drops in 60ml (0.083dKH accuracy)

KH is about 0.74 degrees.

Fish are stressed, but I think that if I had 130ppm of CO2 there wouldn't be any, and I would have more money from selling plants

Questions:
¿Can such a low KH cause problems on PH readings? (I'm using an American Marine Pinpoint PH meter)
¿Is it wise to increase KH to take better/more accurate CO2 readings?
¿Can that be affecting plant's growth?

Thanks for your help.