Ph down buffer.

[Kelvin12]

Hello all,
I have been reading a lot of previous posts about Ph fluctuations and not chasing it with water thats on the acidic side. However I have been using ' Ph down' a few times and that reduces it but then its crept up again to well above my desired / recommended levels 5.8 , 6.0 quite quickly. I have been using this product, ' Ph down ' where the active constitute is Biphosphate. In addition so far I have been using quite a lot of peat and numerous IAL. Everything seems to stabilize for a bit but soon creeps up to around 6.8, 7.0 mark. I am using remineralized RO and thats keeping the TDS quite well within recommended levels .
I have PRL and CRS shrimp.

 

[Maf 2500]

Hope these are what you had in mind

Yes, agree with Darrel @dw1305, looks very much a maple in branching structure etc so Acer negundo it is

 

[Kelvin12]

Good work. Been interesting to follow this one thank you all for the help.

Dirk

 

[Kelvin12]

I tested the Camelia and Maple leaves and was surprised at the results. Not a particularly scientific approach but enough to see if these leaves actually worked in reducing the Ph levels.

Started with two buckets of RO water. 5 litres a piece. Start Ph 4.5
A good two handfuls of each leaves inyo each bucket.
(Not the most scientific measure).

CAMELIA. Day 1.
Almost instantly after a good stir the Ph went to 5.3 then 5.9 after a short time. No idea why this happened might be a question for Darrel on this one.
Day 2, Ph 5.9
Day 3, Ph 5.8 Hopefully coming down.

Don't know if this reading would hold long term but will keep the test going and see what happens.


MAPLE. Day 1.
Same aporoach after a good stir. Start Ph 4.5.
Day 2, Ph 3.8
Day3, Ph 3.8

Pretty substantial drop from Ph 4.5 to 3.8 these Ph readings are way lower than I would require but promising and again will keep testing and lowering the
amount of leaves.

Dirk

 

[arcturus]

I tested the Camelia and Maple leaves and was surprised at the results. Not a particularly scientific approach but enough to see if these leaves actually worked in reducing the Ph levels.

Started with two buckets of RO water. 5 litres a piece. Start Ph 4.5
A good two handfuls of each leaves inyo each bucket.
(Not the most scientific measure).

CAMELIA. Day 1.
Almost instantly after a good stir the Ph went to 5.3 then 5.9 after a short time. No idea why this happened might be a question for Darrel on this one.
Day 2, Ph 5.9
Day 3, Ph 5.8 Hopefully coming down.

Don't know if this reading would hold long term but will keep the test going and see what happens.


MAPLE. Day 1.
Same aporoach after a good stir. Start Ph 4.5.
Day 2, Ph 3.8
Day3, Ph 3.8

Pretty substantial drop from Ph 4.5 to 3.8 these Ph readings are way lower than I would require but promising and again will keep testing and lowering the
amount of leaves.

Maybe you could repeat this test with remineralized RO water. The dKH of the RO water should be very low, and the pH readings you are getting (including the pH swing with the Camelia) might be influenced by this. With some carbonate buffering in the RO water the results should be more accurate .

 

[Kelvin12]

This was straight RO water I used. What TDS would you suggest. I can certainly remineralise easy enough. I have plenty of leaves for a re-test. as we are going into autum now and leaves are plentiful. I was actually thinking of doing another test just to verify anyhow in the next few days.

Dirk

 

[ian_m]

Sarted with two buckets of RO water. 5 litres a piece. Start Ph 4.5

You cannot measure the pH of RO water, its value will likely be all over the place as not really an excess of H+ ions (pH) in RO water. Google for more technical reason or wait for @dw1305 to give a more concise answer.

 

[arcturus]

This was straight RO water I used. What TDS would you suggest. I can certainly remineralise easy enough. I have plenty of leaves for a re-test. as we are going into autum now and leaves are plentiful. I was actually thinking of doing another test just to verify anyhow in the next few days.

Just add some carbonates to the water. 2° dKH should be enough for this task. You can use any of these to get there (copied from James' planted tank):
1.5g NaHCO3 in 25 litres of water = 2 dKH
1.8g KHCO3 in 25 litres of water = 2 dKH
1.2g K2CO3 in 25 litres of water = 2 dKH

As an alternative, mix 50% RO with 50% tap water. You should also have sufficient KH if you do that. Looking forward for the results of this experiment

 

[dw1305]

Hi all,
edit: what @arcturus says

Almost instantly after a good stir the Ph went to 5.3 then 5.9 after a short time. No idea why this happened might be a question for Darrel on this one.

It could be absolutely anything, probably just a <"substance on the exterior on the leaves">, possibly just dust. It is the issue that @ian_m mentions, pH isn't a useful measurement in pure water.

What TDS would you suggest. I can certainly remineralise easy enough.

Probably about <"2dKH carbonate buffering"> and then add some <"neutral salt"> (NaCl, KCl, CaCl2.2H2O etc) to raise the conductivity to ~500 microS (300 ppm TDS). The pH meter should then read somewhere near pH8 and also stabilise relatively quickly. The neutral salt doesn't change the pH at all it just raises the conductivity of the solution and anywhere near 500 microS will do.

1.5g NaHCO3 in 25 litres of water = 2 dKH
1.8g KHCO3 in 25 litres of water = 2 dKH
1.2g K2CO3 in 25 litres of water = 2 dKH

Have a look a the the Hornbeam (Carpinus betulus) thread on <"Apistogramma forums">

cheers Darrel

 

[Kelvin12]

ian-m, never knew Ph was unreliable in RO. That always worried me that I was getting the odd reading and was blaming the meter. I binned the ebay special for that reason and bought a Hanna meter.
This forum sure is a learning curve.
Dirk

 

[Kelvin12]

Should I use the same amount of leaves in the 25 lt mix, a generous handful. I am thinking the 25 lt would be a more reliable result rather than the 5 lt bucket currently.
Dirk

 

[arcturus]

Should I use the same amount of leaves in the 25 lt mix, a generous handful. I am thinking the 25 lt would be a more reliable result rather than the 5 lt bucket currently.
Dirk

Hmmm... good question. The concern with using 25l container is that the pH drop might be rather small unless you add a bunch of leaves to it. But the larger container would better simulate the conditions in a tank. Let's wait for the input of those who have experience with botanicals!

 

[X3NiTH]

If anyone is having problems sourcing the correct botanicals for acid pH moderation and just wants to cut to the chase then this is the molecule you are looking for.

The Behemoth that is C76H52O46, Tannic Acid.

For @Kelvin12 in Oz he can go here for a supply, maybe buy some extras to put all that acid to use and brew a cheeky Chardonnay!

Anyone in the UK want some can get it here.

 

[ian_m]

ian-m, never knew Ph was unreliable in RO. That always worried me that I was getting the odd reading and was blaming the meter. I binned the ebay special for that reason and bought a Hanna meter.
This forum sure is a learning curve.
Dirk

A good experiment I remember seeing was, place pH probe in low pH calibration solution (4 ?) and then in RO water and you get one pH reading, below 7 generally, then in high pH calibration solution (11 ?) and back in RO water and you get a different reading, above 7 generally. This is because RO water has no buffering capacity, buffering capacity is the ability of water to keep pH stable as acids or alkalis are added.

Generally you need a hardness above 4dH before you can get reliable pH (and quite a few tests) a meaningful reading. This can easily be achieved by mixing RO water with tap water or adding calcium/magnesium carbonate to the right levels.

 

[Kelvin12]

Thank you X3NiTH for another option had no idea these chemicals were out there. I have been making notes of all these possibilities.
Tannic acid might be a good excuse to get back into home brewing..,...

Dirk

 

[Kelvin12]

Thank you ian_m, interesting post your one. Ph is a weird one to get the head around. Thankfully this forum and yourself are happy to share the knowledge and offer explanations.

GH hardness is a bit low in the PRL tank (2dGH) so I need to raise that to 4GH so perhaps I have been getting an incorrect Ph reading all along.

Dirk

 

[Kelvin12]

Leaves are all the tanks now, (sumps in bags) both maple and camelia and all looks very stable. Just need to add leaf litter to the substrate now after the rebuilds to keep the inmates busy and happy.

Dirk

 

[ian_m]

Also be very careful about chasing mythical cure all numbers.

Many people expend great effort achieving some value or other (ie pH of 6.3465) for a reason they can no longer remember and fail to notice their plants are extremely unhealthy, algae is having a whale of a time and live stock dying....but hey ho their pH is accurate they falsely believe.

I would severely doubt a hobby user could get a pH more accurate than 0.5, taking into account quality of test kits, especially test kits compared to pH probes, and the simple fact the water has loads of other stuff in it.

 

[Kelvin12]

Yes good point I am certainly realizing this fact especially with this particular discussion. So much I didn't know and still don't..... I was trying to achieve an exact number that I would probably never get to.

Dirk

 

[Kelvin12]

Well the leaves are working extremely well. Took a lot to get the quantities right but all seems quite stable at the moment with Ph at 6.5. Very happy here.
Camelia is ahead in the stability race but the tannin is about the shade of a strong cup of tea maybe slightly less. The maple isn't to far behind and the tannin is slightly less. Probably would not be suitable to a lot of people but great for shrimp breeding. Mine haven't started yet so going on others recomendations.

The ammount of leaves needed is quite high. For my quantity of water 70 lts and 120 lts its basically 10 lt buckets loosely filled. I have sumps so the leaves aren't in the tanks themselves. A small nanno pump helps in the circulation in the sumps.

Got to thank Darrel here for the above idea and plus the citric acid tip to get the Ph up a tad when needed while the leaves settled. That citric sure is strong and a pinch was all that was needed.

Dirk.

 

[Cédric]

That is the issue, for a buffer to work you have to have an excess of undissolved salt (the buffer) that can go into solution and this means that the TDS will always be high when you use them.

Hi Darrell, I thought HCO3 were very soluble salts (are they ?). If so, where the excess of undissolved salts in buffer system based on carbonate come from ?