Pure rainwater

[Brengun]

Gosh I miss Bob, especially when I have water questions but maybe some lesser mortals can help me?

I used to use all townwater but omg their ph fluctuated from 7.4 down to 7 with no kh at all. Our street plumbing is positively ancient and every so often they bore out the lines of tree roots and flush the whole mess through. None of my plecos ever bred for me in the town water either and I did lose a few mysteriously.

I started using 1/2 town water and 1/2 rainwater but nothing ever bred for me then either.

Now I am back on all pure rainwater and straight away I got corys spawning, L397 spawns and even something new, a L201 spawn.
My rainwater is tds 007 to 011 and thats in the stored water change drums. Kh is 1, gH is usually 1 and ph is usually 5.7 to 5.9.

I would buffer up the drums water except each one of my pleco tanks is different and I think its something to do with their gravels. Some will sit up on 7.3ph, some will sit nice on 7ish but some are a little iffy in 6.6 and they will drop further if I don't keep an eye on them and add a pinch of buffer every so often.

What I worry about is that my water being so pure could be deficient in mineral goodies like potassium, calcium, magnesium and stuff.
I looked at some additives but there is copper in some and I have tons of cherry shrimp who would absolutely hate me putting copper anywhere near their tanks, so thats out.

I tried Kent marine ro right but it sent the tds into a wildly high level so I never really knew if the tank was needing a waterchange or not.

Other ph setting sorts also seem to send that tds up high and I don't think my fish particularly like it. They seem less active and lethargic and tanks I used them in seem to be lacking in many shrimp as well. Perhaps those ones have high phosphates or something? May explain the tds jump.

Lately I tried aragmilk for the mineral goodies (just a few drops per foot of water), aquasonic kh generator as a buffer, and aquasonic amazon liquid for any other minerals and vitamins the aragmilk might have missed.

Trouble is on some tanks I still have to keep a close eye on dropping ph's.
Even using a fair bit of buffers one little 2ft tank which prior to wc has ph 6.6, kh1, gh2 I did wc and had ph 7.5, kh still 1, gh still 2. What the?
I just checked the tank two days after wc and the ph is back to 6.6.
Its driving me nutty! Not that 6.6 is bad but I know by the end of the week when wc is due again it could be 6.4 or even 6.2 and thats getting darned close to a ph crash for my tank.

Thats the worst tank, the others are no where near that crazy with ph. Maybe I need to change part of its gravel with some of the other tanks or something? Its a thought.

Anyway in a further quest I have now had a good read up on seachem stuff and am going to try Seachem equalibrium. Yeah I know its for plants but its got all the mineral goodies I am after without the nasty salts and copper in it.
It kind of read that you can put in as much or as little as you like according to what your individual tank needs and what gh you want and it will still work, so going to give that a go when it arrives. What do you think? Anyone used it before?

For buffering I am looking for low tds in that too so I am getting a little bottle of seachem alkaline buffer and to bring it down to about ph 6.9 I will use a little of the seachem acid buffer as well. Hoping the no phosphates label means low tds.

Its all a try it and see learning curve and I am terrified I will make my fish unhappy rather than happy so I just do my best and not go too drastic, after all, they did breed in pure rainwater before, I just want them to be healthy forever too. :thumbup:

 

[scatz]

I used to use pure rainwater (when i had enough to) but had real problems with ph swings as the rain water had 0 tds and 0 kh, I didn't want to start adding remineralising powders/ solutions as i had no way to really know which minerals etc it was missing.
I now use a mix of rain water and tap water (2 parts rain to 1 part tap) but my tap water is a lot different to yours, my tap water tds was way over 300.
I'd try different ratios with tap/rain water to try to get the water the way you want it, trial and error.

 

[bigbird]

I use a ft tank as my storage unit, so I use 1/2 rain and 1/2 tap and have 8 almond leaves in them. I let this sit for 1 week and find it more stable. I do not heat the water, but pump direct from the 4ft water tank. I do however test before a change, as you indicated, the tap water results vary on if we had more rain etc. cheers jk :thumbup:

 

[dw1305]

Hi all,
I'd definitely carry on with 100% rain-water, but just treat the rain-water like RO. If you don't mind playing about with some chemicals you can use the calculator at the the excellent "James' Planted Tank":
<http://www.theplantedtank.co.uk/RO.htm>

The other way would be to just use some "oyster shell chick grit" and Epsom salts (MgSO4.7H2O) for dGH/dKH.

Have a look at this thread: <http://www.plecoplanet.com/forum/showthread.php?t=9323>

I used to use pure rainwater (when i had enough to) but had real problems with ph swings as the rain water had 0 tds and 0 kh,

A lot of people won't agree with this, but pH is a totally useless measure as you approach pure H2O, in fact I would go further and say that pH, without some indication of dKH, is a useless measure at all times.

Because pH is a ratio it doesn't tell us anything about the amount of acids and alkali, just their ratio. In low TDS water any change in the number of acids and alkalis will cause huge changes in pH, although the actual numbers remain very small. Have a look here for a bit more explanation: <http://www.plecoplanet.com/forum/showthread.php?t=8904&page=2>

There is also a bit more in this post, which explains why Bob could, and Brian can, cut their RO with tap or HMA to give the dKH they want. <http://www.plecoplanet.com/forum/showthread.php?t=8744&page=3>.

cheers Darrel

 

[Brengun]

Thanks for the links. Will certainly be reading them as every little bit helps and I seem to be totally thick in understanding every facet of water chemistry.

I have had a good report from someone using the seachem equalibrium on another forum so really busting for it to arrive now so I can try it and do testing on it.

 

[ccole]

fantastic info people- ever useful for my ticking brain. Just one questions- i've been away for a while so what happened to bob? respects cc

 

[Tener ds]

fantastic info people- ever useful for my ticking brain. Just one questions- i've been away for a while so what happened to bob? respects cc

check ur pm,s m8.

 

[Brengun]

I have my gH seachem equalibrium now and although its more suited to plants, the potassium, magnesium and calcium salts look like they will suit my plecos as well.

I am keeping records of tds/pH/kH/gH and wc's and just introducing everything gradually.
The gH does push up the tds a bit but nowhere near what cheaper brands of gH do.

I am also using Seachem alkaline buffer which will top out at about 7.8pH. I haven't quite put full dose rates in yet but I am getting there. So far I can easily get a kH of 2 and sometimes even 3 no probs.

Oh I should add, I am not mixing this in my wc drum, it is added to each tank according to what that tank needs. Some of my tanks with more calcium carb in the gravel have a natural buffering action anyway and some have none.

To offset the higher pH caused by the alkaline buffer I am using Seachem acid buffer. Neither of the buffers contain phosphate so it barely affects the tds reading at all.
Makes a lovely fizz when you add the alkaline and acid buffers together.
Add a bit of blackwater extract to the cup as well and it makes a lager beer foam on the top lol.

Anyways, with my particular water I am finding I have to dose more acid buffer than seachem has recommended on their bottle dose rates. I'm not going too crazy with it as pulling the pH down will be a gradual over a period of time thing.

So far I am pretty happy with it all and I will continue keeping records and perhaps do an article on it one day?

 

[beencees]

Add a bit of blackwater extract to the cup as well and it makes a lager beer foam on the top lol.

Hahaha! You're a crack up Bren.
Maybe if they all get a bit tipsy they might be in the mood for some lovin

 

[dw1305]

Hi all

To offset the higher pH caused by the alkaline buffer I am using Seachem acid buffer. Neither of the buffers contain phosphate so it barely affects the tds reading at all. Makes a lovely fizz when you add the alkaline and acid buffers together.

Bren, you need to stop now, it is a con, you can just use the Seachem alkaline buffer (although this is probably a very expensive way to buy sodium bicarbonate*) or add a small amount of "Epsom Salts" and some oyster shell grit, there is a reason for the fizz, the "Seachem acid buffer" isn't a buffer at all, and in my opinion Seachem are deliberately aiming to mislead and confuse the people who buy their products.

Have a look at the ingredients, it will contain sodium bisulphate - (NaHSO4) <[ame="http://en.wikipedia.org/wiki/Sodium_bisulfate"]Sodium bisulfate - Wikipedia, the free encyclopedia[/ame]>, and this will disassociate to H2SO4 (sulphuric acid), and this is what is reducing the pH (and causing the fizz).

They know people wouldn't add sulphuric acid or swimming pool sterilizer to their tank, but that is what they are selling, for a huge mark up, with a name that is chemically incorrect (it isn't a buffer, buffer is a technical term with an exact meaning) at best.

It says

should be used with the alkaline buffer" and "Neutral Regulatorâ„¢ & Discus Bufferâ„¢are phosphate based buffers providing a very strong and stable buffering system. Alkaline Bufferâ„¢and Acid Bufferâ„¢are non-phosphate buffers, which although less stable than a phosphate buffer...."

from <http://www.seachem.com/support/FAQs/AcidBuffer.html> "

This "buffer" is an acid and not a buffer at all. It is neutralising the carbonates, and out-gassing the CO2, so in effect it is removing the carbonate buffering you have added to your rain water. If you add enough "Acid buffer" it will remove all your carbonate hardness and the pH could drop back to very low levels.

cheers Darrel

* Seachem won't tell you what their alkaline buffer contains, other than it is "sodium bicarbonate based".

Kent does supply ingredients for "Kent's pH Stable", and I would be willing to bet that they aren't much different.

Chemical percent
Sodium bicarbonate <80
Sodium carbonate <20
Magnesium carbonate <5
Sodium borate decahydrate (borax) <5

So basically sodium bicarbonate ("bi-carbonate of soda"), and sodium carbonate ("washing soda"), both of which will increase the GH and pH, but not the KH (they will disassociate to Na+ ions).

The small amount of magnesium bicarbonate will increase the KH marginally (Mg2+ ions), but it is really in there as the "anti-caking" agent, they add it to table salt "Because of its water-insoluble, hygroscopic properties MgCO3 was first added to salt in 1911 to make the salt flow more freely." It is also the ingredient of heart-burn tablets "milk of magnesia".

The "borax" (sodium tetraborate decahydrate) is actually the pH buffer, it is a very alkaline buffer and would buffer the water up to about pH8 or higher if there was more of it. The "decahydrate" bit just means the salt contains a lot of water (Na2B4O7·10H2O), it's the 10H2O.

 

[Brengun]

Thanks for the tip. I will use less alkaline buffer and reserve the acid one for when I am daydreaming and stuff up the alkaline dose thinking its a bigger tank lol. Don't laugh, it happens more than you think.

 

[dw1305]

Hi all,

I will use less alkaline buffer and reserve the acid one for when I am daydreaming and stuff up the alkaline dose .....

It will work then, although the conductivity will rise as the sodium sulphate (Na2SO4) (product of the acid/base reaction) goes into solution.

H2SO4(aq) + Na2CO3(aq) --> Na2SO4(aq) + H2O(l) + CO2(g)

cheers Darrel

 

[Brengun]

An update. Good news, I just did 12 wc and 4 tanks after buffering read perfecto! The rest are pretty darn close.

I have just been adding a little more seachem equilibrium (gh) each week until it gets to what I like of 6 drops for the api gH test.

I have noticed that since equilibrium has calcium in it, sometimes it does cross over and buffer the kh a little as well. So now I do the gH first and leave it an hour or more to settle, then test gH and kH and add what ever little bit of seachem alkalinity buffer I need. It does save pushing the pH up higher than it needs to be.

kH of 4 is great but if pH is getting a little high (up to 7.5 pH sometimes) then I am happy with kH of 2 which will hold the pH pretty well for a week between water changes.

It has taken weeks for my tanks to finally adjust to decent levels but now I think if I keep an eye on things and add just a little bit of buffers, my tanks and the pH should be pretty stable.
I think the fish are loving the added minerals as they all look much happier now.

Did I ever put up the ingredients of Equilibrium? Here's the goodies my fish were missing out on with me using straight rainwater with no additives.

Guaranteed Analysis (Amounts per 1 g)
Soluble Potassium (K20) 23.0%
Calcium (Ca) 8.06%
Magnesium (Mg) 2.41%
Soluble Iron (Fe) 0.11%
Soluble Manganese (Mn) 0.06%

Derived from: potassium sulfate, calcium sulfate, magnesium sulfate, ferric sulfate, manganese sulfate.

I did consider buying the ingredients and making my own mix but its all balanced in the seachem and so much simpler. :thumbup:

 

[dw1305]

Hi all,

Did I ever put up the ingredients of Equilibrium? Here's the goodies my fish were missing out on with me using straight rainwater with no additives.

Guaranteed Analysis (Amounts per 1 g)
Soluble Potassium (K20) 23.0%
Calcium (Ca) 8.06%
Magnesium (Mg) 2.41%
Soluble Iron (Fe) 0.11%
Soluble Manganese (Mn) 0.06%

Derived from: potassium sulfate, calcium sulfate, magnesium sulfate, ferric sulfate, manganese sulfate.

Looks all right. No sodium (Na), which is good, certainly shouldn't do any harm to your fish, and your plants may well benefit.

cheers Darrel