First attempt at fishkeeping and aquascaping - 60L tropical aquarium

[FrozenShivers]

I would just add that at a pH of 6, Ammonia is likely less of a problem, and Nitrite will become very toxic at very small PPM levels. (It's reversed in pH7+ water).

Good to know as I wasn’t aware and I have soft water also!

 

[Bradders]

pH = 6.4 (or lower?)
pH = 6.0 - 6.5 (or lower?)

Thats odd. The water report mean pH testing shows a pH of 8.2. But your tests are showing a pH of 6.0-6.4 - and that includes the tap water testing! Thats quite a difference.

I suspect now you introduced 12 Ember Tetras yesterday, this is going to kick-start the ammonia source and cycle, so I think the next couple of days to a week are going to be interesting in terms of water chemistry. I am currently cycling with a pH of 6.0 to 6.8, so we are not too far off on the pH level.

 

[itudela]

Thats odd. The water report mean pH testing shows a pH of 8.2. But your tests are showing a pH of 6.0-6.4 - and that includes the tap water testing! Thats quite a difference.

I also noticed that. I usually measure the tap water as it comes out (rather cold). Proper measurements with a pH meter equipped with a temperature probe would take into account the temperature, but I would not expect that to result in a difference of 2!

We are around 6 miles away... I am curious if something may be going on that may have that effect between the treatment plant and our home.

I suspect now you introduced 12 Ember Tetras yesterday, this is going to kick-start the ammonia source and cycle, so I think the next couple of days to a week are going to be interesting in terms of water chemistry.

I'll make some popcorn! By Wednesday the cavalry (i.e. new plants) should have arrived. Hopefully we will have made it then.

 

[itudela]

Morning update...

Tank water test results with JBL strips:
NO3 = 10 ppm
NO2 = 0 ppm
GH = 4 - 7 degrees
KH = 0 degrees
pH = 6.4 (or lower?)
Cl2 = 0 ppm

Tank water test results with Aqua are Master Test Kit:
NO3 = 5 - 10 ppm (very weak, but progressively growing)
NO2 = 0 ppm
NH3 = 0 ppm
KH = 0 degrees
pH = 6.0 - 6.5 (or lower?)
PO4 - P = 0 - 0.25 ppm (starting to show a very weak yellow color, depending on background and light)

Tap water looks exactly the same as before with a strip, although the pH seems a bit higher today (6.4 - 6.8) and with a touch of chlorine (0.8 - 1.5 ppm).

On another topic, one of the plants I got seems to be quite happy. I splitted the pot into 4 bits, and although all of them are growing, two of the stems are thriving, throwing roots everywhere. If anyone knows the species, please do let me know! @jamiep, any chance you could know it? You got the other one right.

 

[Bradders]

Tap water looks exactly the same as before with a strip, although the pH seems a bit higher today (6.4 - 6.8) and with a touch of chlorine (0.8 - 1.5 ppm).

I am still perplexed why the 44 water supplier tests done up to June this year, never had tap water lower than a pH of 7.8. But you are getting much lower! How weird is that?! I know these things are never totally bang on, but still.......

 

[itudela]

I am still perplexed why the 44 water supplier tests done up to June this year, never had tap water lower than a pH of 7.8.

I guess the network between the plant and our home. I am going to let the tap water standing and then do another test... And probably check our neighbours' water in case we need a plumber!

 

[dw1305]

Hi all,

That's odd. The water report mean pH testing shows a pH of 8.2.

It is because of the water company using sodium hydroxide (NaOH) injection for <"control of plumbosolvency">.

I am still perplexed why the 44 water supplier tests done up to June this year, never had tap water lower than a pH of 7.8. But you are getting much lower! How weird is that?! I

The reason the values are so strange is that NaOH is a "strong base", so only need a small volume addition to raise the pH. Because it is a "strong base" <"strong and weak bases"> it doesn't add any <"buffering">, all the Na+ and OH- ions are already in solution (it is "fully ionised", there isn't any undissolved NaOH).

In a lot of UK tap water you would have some <"buffering from carbonate ions" (dKH)>, derived from dissolved CaCO3. Calcium carbonate (CaCO3) is a weak base and <"technically insoluble in water">, but soluble in weak acids.

We can ignore the <"sodium Na+ ion in pH terms">, but you only need a very small addition of an acid (proton donor) for the H+ ion to combine with OH- ion and be neutralised as H2O and the pH to return to pH7.

If you have a small excess of H+ ions (from <"dissolved CO2"> etc) the pH will fall below pH7.

cheers Darrel

 

[jamiep]

Alternanthera Reineckii. Maybe the Rosanervig variety, but unsure

​

 

[itudela]

It is because of the water company using sodium hydroxide (NaOH) injection for <"control of plumbosolvency">.

I hadn't thought about that. In my previous job we treated the effluent water from a process line with caustic soda precisely to precipitate heavy metals (which we would coagulate, sediment and then filtrate).

I was thinking the high pH in the treatment plant might be from treating it with limestone; I got the impression from someone from Scottish Water that I met at work that most natural waters in Scotland are acidic in nature, so they bring the pH up with limestone (which is why I initially thought about adding some small chunks to my tank).

The calcium carbonate might add some buffer effect to the tap water (as opposed to caustic soda, as @dw1305 says), but I guess that if enough CO2 was absorbed between the treatment point and my home, it may be perfectly reasonable to have a pH drop if the KH is really low. I mean, a drop of oH from 8 to 6 is two orders of magnitude, but a pH of 6 is (if my math is correct?) 0.001 ppm of protons in practice...

I joined for the plants, fish and snails, but I may stay for the chemistry!!

 

[dw1305]

Hi all,

so they bring the pH up with limestone

They use <"limestone in the catchments"> sometimes, but it has gone a bit out of fashion recently. I'm pretty sure they aren't using it in water treatment, although sodium carbonate (Na(CO3)2) would be an option. Any carbonate compound would add dKH and CaCO3 isn't really soluble enough to be an option.

I know that there has been a shortage of sodium hydroxide (NaOH) <"Has Caustic Soda Become the New Unobtanium?">, but I'd very surprised if anyone is using anything else, by choice, because NaOH gives you maximum bang for your buck <"Poolend & Highgate pH Correction & Plumbosolvency (2017) |">.

The problem with <"calcium hydroxide"> (Ca(OH2)) is solubility. If you had more dGH then you would expect (CaCO3 gives 1 : 1 dGH : dKH) then calcium hydroxide is an option.

cheers Darrel

 

[dw1305]

Hi all,

In my previous job we treated the effluent water from a process line with caustic soda precisely to precipitate heavy metals

That is it, wastewater treatments tend to rely heavily on using sodium hydroxide (or "caustic soda" - (NaOH)) for pH correction, mainly to counteract the drop in pH when using ferric (or aluminium) based coagulants.

We have some bits on <"ferric compounds"> as precipitants for phosphate in waste water.

cheers Darrel

 

[itudela]

Hi all,

That is it, wastewater treatments tend to rely heavily on using sodium hydroxide (or "caustic soda" - (NaOH)) for pH correction, mainly to counteract the drop in pH when using ferric (or aluminium) based coagulants.

We have some bits on <"ferric compounds"> as precipitants for phosphate in waste water.

cheers Darrel

@dw1305, you would have enjoyed playing with the system! Ferric chloride was precisely the flocculant we used, and we brought the water from pH 3 to at least 9.5 to get rid of Ni2+ before discharge. We designed the process thinking we were going to have a lot of Ni2+ in the effluent, but the concentration was not really that high in practice, and we could have almost discharged it as it was after adjusting the pH. Using ferric with a low concentration of heavy metals was actually more difficult to operate that if we had lots of them, as the resulting flocculants were not as consistent as those when you have a lot of metal precipitates after adjusting the pH. We also had Sn2+ and a bit of Cu2+, but that wasn't an issue at all. Brings me great memories...

 

[dw1305]

Hi all,

you would have enjoyed playing with the system!

I mainly play with <"clean water now">. I miss the wastewater work (mainly <"landfill leachate">), although some of it <"was pretty horrible">.

cheers Darrel