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Ph profile

Chrispowell

Member
Joined
18 Apr 2014
Messages
387
Morning all,

Does anyone have a good example of a pH profile from their tank?

I'm going to measure mine and assume we look for a good 1ph drop before lights on followed by a stable pH throughout the lighting period?

Is there any detrimental effects on plants if the drop is greater then 1 or continues to drop throughout the lighting period?

Thanks

Chris
 
Morning all,

Does anyone have a good example of a pH profile from their tank?

I'm going to measure mine and assume we look for a good 1ph drop before lights on followed by a stable pH throughout the lighting period?

Is there any detrimental effects on plants if the drop is greater then 1 or continues to drop throughout the lighting period?

Thanks

Chris

ph-profile-2-jan-22-jpg.jpg


To answer your question, here's my old profile. I'm sort of too lazy to do a complete profile every 15 minutes now.... maybe when I have more free time as my pH variance now is probably not as good (0.1-0.15)
My drop checker is lime green only throughout the photoperiod, it never turns yellow.
 
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Thanks for all the input everyone! It's always nice to see a thread develope!

I started to document my ph levels today, will take a few days but when u have results I will post them up

Thanks

Chris
 
continues to drop throughout the lighting period

This usually suggests you have insufficient surface agitation. Though it might seem counter productive, increasing the surface agitation will off-gas more CO2, which will mean you need to increase the injection rate to hit your target 1.0pH drop. However the net result will be a quicker pH drop, and more stable CO2 levels through the photo period.
 
Is there any detrimental effects on plants if the drop is greater then 1 or continues to drop throughout the lighting period?
Notwithstanding some of the comments above, I have never found a pH drop of greater than 1.0 detrimental to plants. In fact, for most high tech high light tanks somewhere around a 1.4 pH seems to be about optimum. I have tested this in my own tank many times over many years.

But keep in mind that is relation to my very high light tank full of stems. In a tank that is not driven very hard and is full of slower growers there is a law of diminishing returns. Light is the gas pedal. Turn it up and plants need more CO2. Turn it down and they need less.

In a high energy tank keeping CO2 optimized and steady pays dividends. There are loads of ways to get it wrong. Many bang their heads against the wall chasing fertilization theories, when turning up the CO2 is the quickest remedy.

As to a pH profile I have found getting to very near pH peak drop when lights turn on is best. And then the tricky part is keeping that level steady during the lighting period. All of this is based on my personal experience and observations over a long period of time. I have found most scientific studies offer little help to the aquarist, as no one is performing true scientific experiments based on our glass boxes packed with a wide variety plants.

Most aquarist would do better to use trial and error and observation to fine tune their unique ecosystem. But to do so takes time and patience, which not many are willing to do.
 
Hi all, started to do a ph profile..

Can anyone explain what's going on in my video? Tank pH measures one thing - take the water out of the tank and the reading is miles different?!


Thanks

Chris
 
Hi all, started to do a ph profile..

Can anyone explain what's going on in my video? Tank pH measures one thing - take the water out of the tank and the reading is miles different?!


Thanks

Chris
You set the test cup of water directly on the light. I wonder if electrical interference from your LED light is causing the erroneous reading?
 
Yes you are correct! Thankyou!

Now... I'm struggling to get anywhere near a 1.0ph drop!

Water just before co2 on is 6.78ph.

Water just before co2 off is 6.46 (drop checkers are yellow at this point).

Co2 currently on 5 hours before lights! I went back to the in tank diffuser and I can visibly see alot of gas coming from the diffuser.

What further information would assist?

Thanks

Chris
 
Yes you are correct! Thankyou!

Now... I'm struggling to get anywhere near a 1.0ph drop!

Water just before co2 on is 6.78ph.

Water just before co2 off is 6.46 (drop checkers are yellow at this point).

Co2 currently on 5 hours before lights! I went back to the in tank diffuser and I can visibly see alot of gas coming from the diffuser.

What further information would assist?

Thanks

Chris

Remember your 1.0pH drop is supposed to be from a degassed sample of tank water (put some in the jog and leave for 24 hours stirring occasionally), not from the CO2 switch on point in-tank.

It’s highly unlikely your tank gets fully degassed and returns to equilibrium CO2 levels with the atmosphere overnight. I’d wager your 6.49pH reading is, or maybe more than, a 1.0pH drop.
 
Yes you are correct! Thankyou!

Now... I'm struggling to get anywhere near a 1.0ph drop!

Water just before co2 on is 6.78ph.

Water just before co2 off is 6.46 (drop checkers are yellow at this point).

Co2 currently on 5 hours before lights! I went back to the in tank diffuser and I can visibly see alot of gas coming from the diffuser.

What further information would assist?

Thanks

Chris
Some pics of your set up would help tremendously. Provide the specs' of your setup, tank size, filter/pump flow rate, as much detail as you can.
Right off it would seem there is a discrepancy between the drop checker and the ph pen results. Did you properly calibrate the ph pen?
 
Remember your 1.0pH drop is supposed to be from a degassed sample of tank water (put some in the jog and leave for 24 hours stirring occasionally), not from the CO2 switch on point in-tank.

It’s highly unlikely your tank gets fully degassed and returns to equilibrium CO2 levels with the atmosphere overnight. I’d wager your 6.49pH reading is, or maybe more than, a 1.0pH drop.
Yes I agree except for one point. His measured difference between high and low ph is .32. I know a tank will not off gas completely over night, unless maybe one is running heavy aeration. From my experience one recovers about 2/3 - 3/4 of the ph over night. Based on a 1.0ph drop that would be a difference between high and low ph of .66-.75 ph. I guess if one has zero water surface movement, no surface skimmers, low water circulation, the losses could be lower?
 
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Yes I agree except for one point. His measured difference between high and low ph is .32. I know a tank will not off gas completely over night, unless maybe one is running heavy aeration. From my experience one recovers about 2/3 - 3/4 of the ph over night. Based on a 1.0ph drop that would be a difference between high and low ph of .66-.75 ph. I guess if one has zero water surface movement, no surface skimmers, low water circulation, the losses could be lower?

Yes, I would expect it to be a little higher at CO2 on the next day, though I’d imagine a 0.5pH increase overnight is fairly common. However if his drop checker is yellow at the end of the photo period, it would suggest a) far greater than 30ppm CO2 associated with 1.0pH drop is being achieved, and b) there is a low level of surface agitation causing a continuous rise in pH levels throughout the photo period.
 
Yes, I would expect it to be a little higher at CO2 on the next day, though I’d imagine a 0.5pH increase overnight is fairly common. However if his drop checker is yellow at the end of the photo period, it would suggest a) far greater than 30ppm CO2 associated with 1.0pH drop is being achieved, and b) there is a low level of surface agitation causing a continuous rise in pH levels throughout the photo period.

Some pics of your set up would help tremendously. Provide the specs' of your setup, tank size, filter/pump flow rate, as much detail as you can.
Right off it would seem there is a discrepancy between the drop checker and the ph pen results. Did you properly calibrate the ph pen?
Agreed..... this is why I think the ph pen might need to be calibrated. What's even more confusing is if you watch Chrispowell's video when he sticks the ph pen in his tank it reads 6.02!
 
Tank specs..

ADA 90H
90 x 45 x 60

Twinstar 900S turned down 50%

Ro water

Two filters, oase biomaster 600 using stainless steel outlet and surface skimmer inlet.

Jbl crystalprofi 1501 with glass lily pipes.

Eheim surface skimmer

Co2 on at 09:00, lights on at 14:00
Co2 off at 20:00 lights off at 21:00
 

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Interesting @Chrispowell - it certainly looks to me like you're dosing a fair amount of CO2, however I'm also surprised how little movement there is in the tank with two filters on it - the CO2 bubbles don't looks to be travelling very far. The mosses and stems from the middle of the tank and to the right don't seem to be moving at all. Do you have any kinks in the filter hoses? What media do you have in the filters?

I'd also want more surface agitation that you're achieving now, I would raise both filter outlets. I would generally run a lily pipe with the 'bulb' part just below the surface. I'd also consider switching the other stainless steel filter outlet to the rear left corner of the tank to get more circular flow, and put the filter inlets in the either the remaining two corners to promote that flow pattern further, or in both the rear corners to help draw CO2 enriched water through the stems.

The stems themselves aren't looking overly healthy, and though it's hard to tell from the video, it looks like you could have some chlorosis and stunting going on. You say you are using RO water - what is your remineralisation and fertilisation regime?
 
Thankyou for the continued support, I aim to give the tank a good clean down today and move the filter inlet and outlet as suggested. I was always looking to avoid flow at the back of the tank as I was concerned it would affect the growth pattern of the stems?

Current ferts are below, I'm mixing my own ei style with no added remineralisation
 

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