Tropica soil PH buffering

[Sammy I]

Hello everyone I have just set up a new scape using tropica soil and understand that it buffers my PH which it is doing. My tap water is about 21/22gh 12/13kh PH 7.3 (Degassed PH7.9). My tank water is currently PH 6.7/8 which i assume is because of the soil.

+ How long will the soil (27L) buffer my water for until its exhausted?

Here a link to the journal i've started:
https://www.ukaps.org/forum/threads/channelling-my-inner-felipe-as900.59565/

I'm asking this as i was going to use a PH pen to dial in my co2 but i'm guessing i can't until the soil no longer buffers my water? And have to rely on lime/yellow drop checker?

I know my co2 is good because i just took it off my old tank and replaced the diffuser with a large neo diffuser instead of a medium and my drop checker was light lime green in the opposite side of the tank near the substrate during yesterdays photo period.

My old tank is nearly 3 years old with not a lot of soil so nothing gets buffered, so my PH is my degassed tap water value at PH7.9 and during my co2 period it would be 6.8/9 and was measurable with my ph pen achieving the "1 point drop"

But if my new tank is being buffered to PH6.7 i can't measure the 1point PH drop as i doubt my ph can drop any lower than 6ish with a high KH even though i've got good co2?

Thanks

 

[Zeus.]

How long will the soil (27L) buffer my water for until its exhausted?

depends on the hardness of your water it can become exhaust in hard water as the abundance of ions blocks the CEC sites on the AS. I used ADA AS and have hard to Very hard water and I recon it lasted about a year.
With softer water the abundance of H+ ions helps free up the CEC sites on the AS.

With your water you might need to consider using Fe DTPA or FE EDDHA when the buffering is exhausted as I did 😉

 

[Sammy I]

Thanks, i'll keep an eye on it see if it changes over time. So does that mean i can't achieve a "1 point drop" reading with a ph pen even though i would have that drop if the ph wasn't being bufferd by the soil? If that makes sense.....

@Zeus. I used EI dosing on my old tank with DTPA iron mixed in and seemed to do well so hopefully works this time. I have made up 2x 3L batches of both macro and micro solution, do i need to add any excel/easy carbo to either to prevent any moulding?

Thanks

 

[Zeus.]

Thanks, i'll keep an eye on it see if it changes over time. So does that mean i can't achieve a "1 point drop" reading with a ph pen even though i would have that drop if the ph wasn't being bufferd by the soil? If that makes sense.....

The 1.0 pH drop is is pre CO2 on till lights on - best if stable but the DC colour change is a great guide once it catches up with the [CO2]

I have made up 2x 3L batches of both macro and micro solution, do i need to add any excel/easy carbo to either to prevent any moulding?

No thats for Liquid Carbon which can be used as well as CO2 injection esp in the early days. For mould prevention in ferts Absorbic Acid 1.0gram per litre and Potassium Sorbate 0.4 grams per litre is the general recommended dose of many folk- I might just put a 'tad' more in esp if doing big batches best stored in dark cool place or even a fridge and just get out what you need for a couple of weeks helps too.

 

[Sammy I]

Cool so you make up big batches of EI and then only use a month worth at a time? So i cant can't make a big batch and use my autodoser like i would with my old tank? I only use to make 1L at a time. So if i i wanted to make 5L of each solution i would need to add about 5g absorbic acid and 2.5g potassium sorbate to each solution so stop it going mouldy?

Thanks

 

[Zeus.]

What's the point of having it sitting there for months and take chance of mould? Make big batch and top up monthly and avoid the mould, if you have room in fridge/freezer.

 

[Sammy I]

Cool thanks, makes sense

@Zeus. For the 3L i've made up can i just store it in a cold dark place without adding the absorbic acid and potassium sorbate?
Well I'll have 2L of each to store if i use 1L at a time.

 

[Sammy I]

Now i have my first tank inhabitants i've been thinking.... If my water is being buffered to about ph6.7 and my tap water is 7.3 (7.9 degassed), when doing large water changes (usually 70/80%) will the ph change effect my fish and shrimp? Or will the soil pretty much buffer it straight away?

 

[Zeus.]

Now i have my first tank inhabitants i've been thinking.... If my water is being buffered to about ph6.7 and my tap water is 7.3 (7.9 degassed), when doing large water changes (usually 70/80%) will the ph change effect my fish and shrimp? Or will the soil pretty much buffer it straight away?

With a large WC there will also be a pH drop as the water you have added will have lots of dissolved gases which will reduce the pH, always get lots of pearling after a WC as water degases. But the AS will buffer it also dependant on the waters pH- if the waters pH is high it will lower the pH and visa versa. Your Fish and scrimp cope with the pH swing every day with your injected CO2 so for them IMO its just another pH swing in their daily life as an inmate of your tank😉

 

[Sammy I]

Thanks for clearing that up!

 

[demetrisag]

depends on the hardness of your water it can become exhaust in hard water as the abundance of ions blocks the CEC sites on the AS. I used ADA AS and have hard to Very hard water and I recon it lasted about a year.
With softer water the abundance of H+ ions helps free up the CEC sites on the AS.

With your water you might need to consider using Fe DTPA or FE EDDHA when the buffering is exhausted as I did 😉

Would pls explain more about the buffering with Fe DTPA or FE EDDHA?
This is the fisrt time I hear such a thing!

 

[Zeus.]

Would pls explain more about the buffering with Fe DTPA or FE EDDHA?
This is the fisrt time I hear such a thing!

Fe DTPA and Fe EDDHA do not buffer the water.
Fe EDTA needs a lower pH for it to remain soluble

So when the buffering of the aquasoil is exhausted the pH will increase which could result in the Fe precipitating out and there being none available for the plants ' water water everywhere but not a drop to drink'
Hence timing of dosing trace elements can be helpful if injecting CO2 as if done just as lights come on (and you have a stable pH for 4-5 hours) the plants will have plenty of time to get their fill of Fe.
The choice of Fe chelate is more important if you have hard water, folk who have soft water or use RO water are fine with Fe EDTA

Hope that explains thinks clearer and sorry for any confusion

 

[demetrisag]

Dude! I love your explanation! I was in need for some simple explanation on something finally! Something else also I wanted to ask on this subject. I just started a tank too with tropica soil which of course buffers my water. The ph of my tap water is 7.9 but its extremely hard GH 20 and KH17. Now soil is making KH like 0 and ph 6.9. after the buffering capacity of my soil finishes what will happen to my plants?

 

[demetrisag]

Fe DTPA and Fe EDDHA do not buffer the water.
Fe EDTA needs a lower pH for it to remain soluble
View attachment 169174
So when the buffering of the aquasoil is exhausted the pH will increase which could result in the Fe precipitating out and there being none available for the plants ' water water everywhere but not a drop to drink'
Hence timing of dosing trace elements can be helpful if injecting CO2 as if done just as lights come on (and you have a stable pH for 4-5 hours) the plants will have plenty of time to get their fill of Fe.
The choice of Fe chelate is more important if you have hard water, folk who have soft water or use RO water are fine with Fe EDTA

Hope that explains thinks clearer and sorry for any confusion

Dude! I love your explanation! I was in need for some simple explanation on something finally! Something else also I wanted to ask on this subject. I just started a tank too with tropica soil which of course buffers my water. The ph of my tap water is 7.9 but its extremely hard GH 20 and KH17. Now soil is making KH like 0 and ph 6.9. after the buffering capacity of my soil finishes what will happen to my plants?