# ph drop during co2 injection



## widow-maker (7 Nov 2020)

morning

what kind of a ph drop am i looking for during co2 injection? i have been taking the ph before the co2 starts and when it ends and there seems to be a greater drop than 1 iv ordered a ph pen for a more accurate reading but i was wondering if it drops more than 1 is this a sign of excess co2?

thanks


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## JoshP12 (7 Nov 2020)

Hi @widow-maker,

It is ok to "aim" for a general drop. But that drop may not necessarily mean that the CO2 itself is distributed in the tank appropriately. Many aim for about 1.2/1.3/1.4 pH drop - but keep in mind that our methods of testing are poor.

A drop checker is a great method to gauge your CO2 in the tank - so is a pH probe - so are the plants. So use all of the tests together. If your plants show issues, then we want to consider both the CO2 concentration + the distribution of that CO2.

Take your pH at the start of CO2, then right before lights on, then throughout until the end of photoperiod. Your pH should be stableish (+/- .1 ish) throughout the photoperiod and it should be at "maximum" (max pH drop) by lights on so that the plants aren't nutrient limited once they start photosynthesizing (after that initial moment). 

Try not to take the numbers as the be all end all. What you don't want is the pH to drop then at lights on it swings all the way back up and the CO2 is used up - that means the plants don't have enough CO2 for when they are photosynthesizing.

If you have high surface agitation and high injection rate, this will not be the case.

Let's start with this - keep us updated .

Josh


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## widow-maker (7 Nov 2020)

thanks for this i have a power head for circulation and a sponge filter going i read on some forums not to have a air stone or sponge filter going?

this is the first attempt at co2 and finding it hard to try and work out if i have enough co2 or not enough this is the colour of my drop checker i have a kh tester so i thought i would use the chart i found to check the co2 ppm but i’m using fluval stratum which reduces your kh to zero so that renders the co2 chart useless.

i put a couple of fish in last night but noticed there were breathing fast so i took them out and reduced the co2. im going to test the ph drops with the pen next.


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## JoshP12 (7 Nov 2020)

Hi @widow-maker,

Maybe throw some specs up for us of the entire tank: https://www.ukaps.org/forum/threads/please-read-the-guidelines-for-plant-help.60671/ 

Then we can kind of gauge how to move forward. 

The color looks "ok" but without context, it can be hard to tell. 

The articles at the top are ALL excellent reads:




Josh


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## widow-maker (7 Nov 2020)

hi i have a 100 litre tank reduced it to around 3 bubbles a second have around 20 cuttings and a amazon sword fluval plant 3.0 light fluval stratum substrate turn on co2 11am lights on 12pm co2 off 7pm lights off 8pm tank fully cycled use tnc complete food lite due to me having phosphate and nitrate in my tap water but now i find out fluval strratum removes phosphate and kh i tested for phosphate have zero. have quite alot of hair algae but i think that’s because the lights were set too high


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## JoshP12 (8 Nov 2020)

Hi @widow-maker, please update all of the details found below: 
1. Size of tank.
2. Filtration.
3. Lighting and duration.
4. Substrate.
5. Co2 dosing or Non-dosing.
6. Fertilisers used + Ratios.
7. Water change regime.
8. Plant list.
9. Inhabitants.
10. Full tank shot.

There are several variables to consider and we really need all the information to be able to help. 

Josh


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## widow-maker (8 Nov 2020)

1. 100 litre
2. sponge filter plus fluval u2
3.  fluval plant 3.0 12pm until 8pm
4. fluval stratum
5. co2 2 bubbles per second 
6. tnc complete lite 3 times a week
7. weekly water change
8. Rotala Rotundifolia Indica
amazon sword
java moss
bacopa
9. nothing yet iv added a couple seemed to be breathing fast took them out

im not sure if two bubbles a second is too much?


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## lilirose (8 Nov 2020)

I would manually remove all the algae that you can, including cleaning the inside of the glass.

Bubbles per second is not really a precise metric for "how much CO2" as bubbles vary in size- you should go by the drop checker, assuming it's properly placed inside the aquarium- I actually can't see it in any of the tank pics, but I might be overlooking it.


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## widow-maker (8 Nov 2020)

i’m going to go through and remove all that algae i thing that was because i had the lights far too high


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## dw1305 (8 Nov 2020)

Hi all, 


JoshP12 said:


> A drop checker is a great method to gauge your CO2 in the tank





lilirose said:


> You should go by the drop checker, assuming it's properly placed inside the aquarium- I actually can't see it in any of the tank pics, but I might be overlooking it.


I'm <"not a CO2 user">, so I don't have any practical experience of adding CO2, but I'd definitely <"get a drop checker">, even if you use the pH pen to get a pH profile.

cheers Darrel


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## widow-maker (8 Nov 2020)

i have a drop checker its green but they dnt seem very accurate i can have 5 bubbles per second and 1 bubble per second and its still green


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## Zeus. (8 Nov 2020)

Any fish you add to a CO2 injected tank will breath faster once CO2 is switched on, any fish introduced to new tank will also breath faster for some time as its a new tank. Fish can take a few weeks to a just to higher [CO2] some faster than others, if their gasping at the surface then they are starting to struggle, if they get over excited in high [CO2] they may go belly up, I had some that use to go belly up when I fed them during main CO2 period so I fed them when main CO2 period was over, the same fish was always gasping at surface during main pH drop then fine once pH drop was over.
If the [CO2] get too high everything will be at the top off the tank snails the lot, too high and you could lose them all.
BPS isn't an accurate way of measuring the injection rate, its more of a means of allowing a little method for adjustment.
Here short vid of my injection rate

2-3 BPS isnt a high rate of inject for a 100l tank by any means.
Looking at the pics of your tank I think the positioning of your filter and powerhead could be improved to give better flow, getting good flow in a CO2 injected tank is critical to success and the plants should be gently swaying in the flow it the tank. I think the powerhead above the filter (if it fits) would work better or the filter and powerhead working together. CO2 diffusor under the powerhead, when you have it right the CO2 bubbles should go to the other side of tank and then go down to substrate level, for which you will need good flow.
Take the air out or only use at night as it will drive off CO2
Ignore the pH chart it wont make life any easier, do a pH profile, take pH before CO2 on every 30 mins till CO2 off and at lights lights on. pH should be stable from lights on till CO2 off, I class stable as same pH +/-0.1pH. getting a stable pH is hard but key to sucess.
Your photoperiod seems a bit long, 5-6 hours should be plenty until you have the algae under control and plants are filling in.
Your plant biomass is a little on the low side so a few floating plants will help short term and help control the algae also.
it normally takes 2-3hrs to get a decent pH drop, only rarely with duel injection does a user manage to do it faster.
The DC colour change you have is fine, however it is the [CO2] in the past (about 2hrs earlier) but using a pH profile along with the DC colour is all I use.
Adjust the injection rate until you have a stable pH *FIRST* then DO not adjust it again,  just time how long it takes to hit your target pH the time it takes is the time it takes, adjusting the injection rate to decrease the pH drop time will mess up the stable pH. If you are using a duel injection with twin timers and solenoids it makes life easier- but few folk use them due to cost.
I would not use TNC lite even if I had excess NO3 or PO4 in my tap water. I would use TNC complete as its the same cost and the weekly 50% WC will take care of any excess nutrients. With a 100l tank I wouldnt use TNC complete either due to cost. Going down the DIY route will save you money and have more control APFUK do a starter kit which will last you years for about the same cost of a litre of TNC


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## widow-maker (8 Nov 2020)

what kind of a ph drop am i looking for please? i have already ordered a ph pen to get a more accurate reading rather than the api test kit i have  been using and im going to move out the sponge filter i been using and put a air stone on a timer


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## Zeus. (8 Nov 2020)

Personally I would aim for over 1.0pH, however if you mess up you could kill all your livestock. Even a small pH drop 'if' *stable* for first 4-5 hrs of photoperiod can have impressive results. A stable pH is more important than a bigger unstable pH drop 
It can take many tries to get it stable, change one thing in tank (power head/different filter media/dirty filter media) and need to pH profile again


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## widow-maker (8 Nov 2020)

so i would do a ph profile with the lights off?


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## Zeus. (8 Nov 2020)

widow-maker said:


> so i would do a ph profile with the lights off?


No, lights come on at normal time taking pH as lights come on, when lights come on ideally the pH should remain stable from then on till CO2 off


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## widow-maker (8 Nov 2020)

this is becoming more like a chemistry lesson haha so a ph drop of 1 will give me around 30ppm co2 so im thinking a greater drop than 1 will give me more than 30ppm thus killing my fish


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## dw1305 (8 Nov 2020)

Hi all,


widow-maker said:


> this is becoming more like a chemistry lesson haha so a ph drop of 1 will give me around 30ppm co2 so im thinking a greater drop than 1 will give me more than 30ppm thus killing my fish


Yes, that is <"what we think">. As you can see (from all the <"linked threads">) there is both <"chemistry and uncertainty">involved.

cheers Darrel


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## Chrisjb330 (8 Nov 2020)

What are your settings for the Plant 3?


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## widow-maker (8 Nov 2020)

i did have it set on the default planted tank but i had a algae explosion i think the light was too high... unfortunately complete guess work. find attached my new settings


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## Chrisjb330 (8 Nov 2020)

I have this light and find theres too much to play with and no single good setting that ive found.

Look at Bentley Pascoes videos. 

Ive also been using this which is a low but did give me growth. Ive since adjusted it to give more light for longer last week.


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## widow-maker (8 Nov 2020)

i be honest i find the light just too complicated i found someone on a forum he said his light settings was ok i just copied them the algae explosion seems to have stopped now im not sure if it was the change of the lighting or something else


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## Chrisjb330 (8 Nov 2020)

A great wise Zeus once told me only to change one thing at a time.


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