pH Controller

Marc Jackson

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:bookworm: I've budgeted for a pH controller to look after the solenoid being on or off. I'm not aiming for a aquascape, just a planted 4ft x 2ft tank and a community of fish. I have used the CO2 Supermarket set-ups before but find the drop checker a bit hit and miss, ideally I want to keep the pH somewhere around 7. Will the electrode hurt the fish? :wideyed:
 

foxfish

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Ph controllers are not popular, most folk much prefer a simple timer.
They don’t offer the consistency that a well set up and fine tuned system will, by their nature the PH must fall before they switch on and rise before they switch off.
Fluctuating C02 can encourage algae.
Of course there are a few people who swear by them but not many.
 

hogan53

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No....;) the electrode is encased in some sort of permeable membrane!

I've used a Ph controller...never found them a problem to use...and got good results,they can be expensive to purchase, if you go Dennerle!

The electrode probably needs replacing every 12 to 18 months!
Calibration....needs redone every so often...its horses for courses...it depends if you want to invest hard earned cash and time on another piece of kit!
hoggie
 

Zeus.

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I use one but only for the pH drop via my PLC. I would say don't bother just get a decent pH pen for doing your pH profile ;)
More stable pH profile without contrlor but hard to do.
 
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Oldguy

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pH controller
The pH electrode will need to be cleaned every now and again to get reliable results.

pH pen & TDS pen are good investments.

I use cheap electromagnetically time switches for CO2 solenoid and photo-period control.

Also observe your fish and plants. When fish are bright eyed and bushy tailed and plants are growing then all is well.

It would appear from posts from the real planty people that a good way to start a planted tank is with no livestock and very high levels of CO2, then lean off over time before introducing critters.

Circulation of CO2 & other nutrients is as important as dosing.

Happy tank keeping.
 

X3NiTH

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The UP Aqua controller has a finer switching variance than the Weipro (that's the two cheapest models out there), it also has two point calibration and it can also work in reverse mode (stated that it can be used for a calcium reactor) which is when the pH drops past the set target point it will switch on (I have used this mode successfully to run CO₂ constantly and then use it to control air to increase offgassing of CO₂).

From my perspective CO₂ controller pH variance has never been a cause or an accelerant for algae in my tanks but then again I run a decent level of CO₂, the only algae that bugs me now and again but remains a constant presence is BBA and that's only in areas that get really high flow (Java fern tips especially and the occasional Buce leaf that I won't remove just because of it). I also have a really lurid green GDA patch on the glass due to light spill from the tank next to it, it's only spreading locally but I'm not going to scrape it off any time soon because I've spotted that it's a Cyclopia feeding station. I'm currently running haphazard CO₂ in one of my tanks because the probe no longer calibrates and hold its value, it's totally done for and I haven't replaced it yet but it lasted well over a year and it was the cheapest I could find on eBay for about £7, this tank only ever gets diatoms on the glass where light is at its highest (also adjacent to the lurid green GDA in the other tank) and BBA just dies in it, badly fluctuating/intermittent CO₂ hasn't encouraged it.

The one thing I will say that a controller is not suitable for is if there is anything in the tank that can affect the carbonate hardness over a short period of time such as an active substrate or additives (either taking KH from the water or adding to it). Controlled CO₂ into a tank with rising KH (in turn pH will rise) means excess CO₂ beyond intended will be injected and this can be a danger to tank inhabitants if you don't notice this (a drop checker will get progressively greener/yellow as KH rises and the pH climbs, the controller just keeps trying to reach that drop though). The reverse situation (loss of KH drop in pH) is more of a problem for the plants as they get progressively less CO₂ over time, here specifically is where there is an opportunity for algae to grow as the plants will start to suffer releasing organics into the water that algae feed from.

If you need to know anything more feel free to ask.

:)
 

Zeus.

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The one thing I will say that a controller is not suitable for is if there is anything in the tank that can affect the carbonate hardness over a short period of time such as an active substrate or additives (either taking KH from the water or adding to it). Controlled CO₂ into a tank with rising KH (in turn pH will rise) means excess CO₂ beyond intended will be injected and this can be a danger to tank inhabitants if you don't notice this (a drop checker will get progressively greener/yellow as KH rises and the pH climbs, the controller just keeps trying to reach that drop though).
Yes been there, as the acidic buffing capacity of ADA AS runs out
 

zozo

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The statement pH controllers cause fluctuating CO² levels in the water is somewhat illogical.. :) Matter a fact contrary is actualy true. I'll try to explain..

Assuming you do a weekly water change anyway as it is a regular maintenance rule for High Energy CO² aqauriums. And you have a stable Kh value and you use a pH profile to determine the CO² contents. Than you calculate X drop in Ph is X ppm amount of CO².

Than if you use a pH controller switching the solenoid at the desired pH drop, than it is only logical to say no matter how much CO² is consummed it stays at the set ppm CO² within the threshold of the controller which in general is 0.1 pH.

If a pH drop of 1 unit is approx. 30ppm CO² than 0.1 pH drop is 3 ppm.. That's a 3ppm CO² fluctuation for the entire periode adding CO². Because if your pH rises 0.1 unit the controller switches the solenoid back on to add CO² again to make it drop 0.1 pH. Thus you stability in CO² and Ph fluctuates within a 3ppm and 0.1 pH constantly.

----->

Now lets compare this to not using a controller but using a drop checker and a bubble counter as a stable recource of adding CO² with BPS. And we calculate for example 30 bps gives me the 1 unit pH drop and a green drop checker. Now we have a stable 30 bps for the entire periode from 1 hour before lights on till 1 hour before lights off. That bubble count doesn't change its set fixed. Now the plants start to slowly consume CO², that doesn't work like a timer switch it's a slow natural process building up in the plant during the light cycle. And your drop checker needs 2 hours to react to a change in pH. Nobody can give a reasonable number of fluctuation, but looking at it logicaly there definitively as a fluctuation and most probably a greater one that 0.1 pH. Simply because you start adding at 30bps from the time the pllants are still in the dark and you are still at 30bps at noon when the plant co² uptake is highest. This all gives a fixed amount of CO² with a dynamic uptake from the plants.

<-------

Now you may deside about which of both methods above has the largest instability in administering CO². :)

Now simple logic says in regard of CO² saturation in PPM the controller is more stable than the drop checker and bubble counter. And even tho lots of people report algae issues with the use of a controller.. It simply can't be CO² instability caused by the controller causing the Algae. Rather it's stability.

Thus it is only fair to say if you have 30 bps at the low uptake cycle and still 30bps at the high uptake cycle it is more unstable, because more is taken but the amount given is fixed.

Still many people experience this as a more stable method regarding plant growth and algae remedi.

Personaly i have no opinion, i only used CO² for 2 years of my intire aquarium career, thats not enough experience to have an opinion on it.. And i can only say regarding algae it were the worst 2 years of my life. Never seen so much algae before and after.. :rolleyes:

For the question is the electrode or the complete device safe for the fish?..

It's an electrical device that functions as a Volt meter.. It sends a current trough the water and measures the resistance between anode and cathode to come up with a pH value. Having a device like this permanently in the water, than it depends on the power of the currect used if fish in close proximity feel a sensation or not. Fish have highly developed sensory organs on their body.. If all this goes well together with artificial electrical currents in the water still remains in the dark. We actualy do not have any numbers on that.

As long as we don't realy know i personaly think it's fair to assume it can have negative effect on the fish..
 

ian_m

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If a pH drop of 1 unit is approx. 30ppm CO² than 0.1 pH drop is 3 ppm.. That's a 3ppm CO² fluctuation for the entire periode adding CO². Because if your pH rises 0.1 unit the controller switches the solenoid back on to add CO² again to make it drop 0.1 pH. Thus you stability in CO² and Ph fluctuates within a 3ppm and 0.1 pH constantly.
Woooow careful there. This is wrong....pH is a logarithmic scale and 0.1pH drop is NOT 3ppm.

pH is given by the negative log of H+ ion concentration. ie pH = -log10(H+)

Thus going down 1pH is a x10 increase in ppm, this is why a pH controller is so bad, that if it overshoots your required pH for 30ppm by 0.1pH that is now about 40ppm and your fish are now floaters. Considering you are lucky if your pH probe is accurate to 0.1 you can see the issue. This is of course regardless of things other the CO2 affecting the pH.

The calculation is, for instance starting at 30ppm (really want Moles, but that is just a scale factor).

Thus

-log10(30ppm) = pH (ignoring scale factors for real pH)

gives x = -1.48

Now reduce by 0.1pH -> -1.58

Giving a concentration of 10^(1.58) -> 38ppm and floaty fish.

You are much better to use a timer, careful injection rate, a drop checker and maybe a pH pen to get reliable non fish killing pH levels.
 

zozo

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and maybe a pH pen
Than what good is that.. It does the excact same thing.. It measures pH and if the valua tels you i need to up or lower your bps.. The 0.1 from the controller isn't different from a 0.1 from the pocket pen.

Sorry i'm not into the number with a 1% degree of accuracy that was not my intention. Even beeing so accurate juggling numbers still doesn't justify the which hunt on controllers with ilogical statements. Than using a pH pen or controller to get a pH profile to know where you are at with co2 doesn't make much of a difference.. Both are the same electronic device to get to a number. That the controller has a build in relais doesn't change a thing.

You can combine a controller with the excact same method as with a pocket pen and a dropchecker and a bubble counter.. If you do it correctly you have a permanent display on the pH and the controller will never switch it off if the bps is a stable as it shoud be in general consunses.

And it prevents a tank dump if it ever comes to that.. Also this can be called controlling.

And i agree 100% that using a controler for convinience to control the co² levels in general is not the way it should be used. We should stop naming it controllers. It's a simple word "controller" that causes all the fuss and misconseption about what it can do. And why it is used with the wrong intentions.
 
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hogan53

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Good discussion going on here!
Well to put my 2 pennies worth in...my Ph is 7.6...or there abouts!
I cant remember what I set my lower limit at but I think it was Ph 6.8.
I used a Dennerel Co2 drop checker to monitor the Co2 level....(Green)
I never dosed enough Co2 to change the Co2 Drop Checker to Limeade colour when I had fish in the aquarium!
Never had fish issues or Co2 dumping!
KH also has a bearing on the amount of Co2 you should be adding to get a required drop in the Ph.

CO2-Chart-1-1.jpg

hoggie
 

Zeus.

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You are much better to use a timer, careful injection rate, a drop checker and maybe a pH pen to get reliable non fish killing pH levels.
Agree with you Ian except for some of us on WC day there may be more fluctuations. Ian (and others) have there water is degased in your water tub so WC day isnt an issue, but folk like me who use water straight from the tap which is loaded with gases so has more CO2 in it.
My pH drop is about 2.0pH which takes about 35mins on every day of the week except WC day(my PLC records how long it takes to reach target pH), on WC day it takes just over 20mins to reach target pH dependant on size of WC and how long the WC is done before CO2 comes on.

So we should be degasing the WC water before adding it. I get away with it to some extent as the pH controler kicks off my high injection rateonce target is reached

KH also has a bearing on the amount of Co2 you should adding to get a required drop in the Ph.
Had read and hear that from folk also. However I'm sure @ceg4048 did post somewhere the KH/Gh has nothing to do with the [CO2] for a given injection rate, just its pH range and the CO2 used in hard or soft water is the same for the same [CO2] :bookworm: !
 

dw1305

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Hi all,
I cant remember what I set my lower limit at but I think it was Ph 6.8.
I used a Dennerel Co2 drop checker to monitor the Co2 level....(Green)
I never dosed enough Co2 to change the Co2 Drop Checker to Limeade colour when I had fish in the aquarium!
Never had fish issues or Co2 dumping!
I'm not a CO2 user, but if I was that is the route I would go down.

Whatever way you measure the pH you always have the issue that @ian_m alludes to if you aim for 30ppm CO2, any slight increase in CO2 level is going to see off all your fish.
did post somewhere the KH/Gh has nothing to do with the [CO2] for a given injection rate, just its pH range and the CO2 used in hard or soft water is the same for the same
It is a bit of a strange one and to do with the log10 nature of the pH scale. In carbonate buffered water (above about 4dKH) a pH drop of one unit <"will always give you about 30ppm of dissolved CO2">.

The actual workings are towards the bottom of page 4. of <"question about.....">.

cheers Darrel
 

Oldguy

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actual workings
Did have the equation of state for the relationship between CO2, pH and carbonate (as CaCO3). It was a bit of a b@ll breaker to rearrange (mixture of linear and logarithmic factors). In practice not that useful with real waters due to other factors that affected pH.

Tempted with the glass drop checker, but you can get 6.5Kg of CO2 for the price of one and the liquids required.

I try for a smaller pH drop as measured with a meter, lower light levels than 'arc lights' and an acceptable mix of plants and interesting and happy fish.

As insurance against 'sleepy fish' I keep a large air pump, just in case.
 

dw1305

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Hi all,
Tempted with the glass drop checker, but you can get 6.5Kg of CO2 for the price of one and the liquids required.
You can buy "bromothymol blue", and after that you just need to make up the 4dKH solution with NaHCO3 etc.

I think 5g of bromothymol blue is about £10 and would be a lifetimes worth.

I don't have any practical experience of drop checkers, but other members will be able to suggest ones that combine aesthetics with relative cheapness.

cheers Darrel
 

ian_m

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The JBL drop checker is the best and only one I now use as;
- has a built in white strip so easy to see colour.
- Splits in half for easy cleaning and filling.
- Is made of plastic so unlike the many glass ones I have been through does not break when dropped.

Just regrease the rubber sealing O ring every couple of years and it lasts well years...
 

X3NiTH

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make up the 4dKH solution with NaHCO3 etc.
Yeah it's so easy to make, my preferred choice would be potassium bicarbonate simply because it provides an impromptu meal the plants will actually like if you happen to up end the drop checker accidentally in the water like I did the other day, I didn't rush to water change and just left it for a day or so and because I used a higher than standar mix in this checker the KH shot up from 8 to 14 (12L tank, plants only). No drama!

:)
 
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