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Confused on the real ph

W@rlock

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gary.bien82@gmail.com
So i measured my pH hours before my co2 turns on. I'm using api test kit. Result is 6.8 but i thought I'd just try and get high pH solution which resulted 7.8. Which do you guys think it's the correct one? I would hope 7.8 because if it's 6.8 it means i need a 5.8 drop to get the 30ppm target. It might be too low for my fishes.

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it doesn't seem a very good advertisement for API if 2 of their test kits can produce a 1.0 difference in pH readings.

you can test each of them using a reference pH 7.0 solution and verify which test kit is more accurate, and throw away the inaccurate one.
 
Apologies i forgot to say that my test kit is just few months expired if that matters. However before i started injecting co2 i had about 8.2 I'm wondering if I'm not gassing my water. I do have surface agitation maybe it's not enough? Still i would have thought id get 7.6 minimum on high water test. I've saved my water and will let is sit 24hrs then test it again.

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Hi all,
I'm using api test kit. Result is 6.8 but i thought I'd just try and get high pH solution which resulted 7.8.
Do you know how hard your water is? If you are in the UK you should be able to get figures from your water company.
However before i started injecting co2 i had about 8.2 I'm wondering if I'm not gassing my water. I do have surface agitation maybe it's not enough?
Do you have a <"drop checker?"> If you don't you really need one.

cheers Darrel
 
@dw1305 i do have a drop checker that stays green but we all know that there some delay with that. I did another check 1hr before my co2 shuts off and got a steady of 6.6-6.7. I haven't tested my kh & gh. I'll probably have to.
dc76a0be70080dab9f32515043c19305.jpg


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Hi all,
i do have a drop checker that stays green but we all know that there some delay with that.
The drop checker should give you a good estimation of pH (CO2 level), but as you said with some lag time. I'll cc in @Zeus.
I haven't tested my kh.
You should be able to get values from your water company, but if you live in the <"SE half of England"> you are likely to have hard water.

Hard%20Water%20Map%20of%20Uk.jpg


cheers Darrel
 
A DC (Drop Checker) with a pH meter/pen or test papers, I trust the DC colour change as I have good flow in my tanks, if the flow is inadequate or set up incorrectly the DC colour change can vary in different parts of tank. Having good flow/turnover in tank resolves many CO2 related issues. Flow is King of the high tech tank. When my 50l gets overgrow the flow is hindered and my DC colour change becomes unreliable and CO2 levels fluctuate. A good trim resolves the flow and CO2 levels become good again

If your DC is green after two hours and the pH remains stable from lights on till CO2 off job done. However what is stable ? I aim for less than 0.1pH change from lights on till CO2 off - which is hard to achieve with BPS adjustments and takes many days/weeks to get it right.

Once you have a stable pH from lights on till CO2 off do not adjust the injection rate (BPS) again, which is a classic mistake of many folk new to CO2. The pre CO2 on time is the time it takes to reach your target/stable pH - if it takes 2 hrs 43mins that's how long it takes and adjusting the injection rate to shorten this time is a NO-NO.

There are ways of having better/faster control of CO2 injection, however with a single solenoid and 'normal' timers it isn't possible/advised

Unless you have very soft water or using RO/rain water, your dGH and dKH should be fine and the actual pH of your tank is irrelevant unless your livestock needs a specific pH range.

A 1.0 pH drop from CO2 on till lights on is the aim and will achieve 30ppm CO2 - Caution however as your tank may not be fully degassed from the day before. I take a glass of tank water and leave it 24hrs and use that as the base line pH off tank - eg pH off glass of water after 24hrs is 7.6pH then my target pH will be 6.6pH. It doesn't have to be 6.6pH you may be happy at 6.7 or 6.5pH.

Having a stable pH with good flow from light on till CO2 off is far more important/critical than the pH drop/[CO2]
 
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