ph lowering

i need to lower my water from 6.5 to 5.5. it will be a 12x10x10 tank set at 24'c with a sponge filter, no substrate and java moss and riccia plants.
what would be the best way to achieve this?
jamie

Hi Jamie,

I'm interested to know why you need to lower you pH to 5.5. That's pretty low and very few fish require water that acidic.

Raising pH is much easier than lowering it. The safest way to lower it is to us Reverse Osmosis (RO) water. To do that, you need an RO unit. Do a search and you'll find plenty of details on RO.

Another way is to add CO2 to the tank. This is particularly benificial if you have plants. You need to ensure you have a steady flow of C02 so your pH doesn't fluctuate.

However, as I've said many times before, it's better to match fish to your water than to try and match your water to fish.

Before you decide on a method, make sure the fish you intend to keep absolutely require a pH of 5.5. Many of the recommendations for fish refer to their requirements in the wild. As many of the fish in the hobby are tank bred, it's possible that they will do just fine in your water as it is.

I agree with Ken about why have you got to keep it so low but
Mixing RO water can be dangerous too. Low oxygen/orp levels
Ph dropping, not enough minerals in the water.
Humic acid is probably easier and less expensive.

Let us know what fish you intend to keep.

The fish is Ps. Annulatus Guinea,(clown killie)Keeping them in my ph now is fine, but on my understanding for successful breeding of them they need a ph of 5.5.

KenS wrote:

Hi Jamie,

I'm interested to know why you need to lower you pH to 5.5. That's pretty low and very few fish require water that acidic.

Try breeding some Apistogrammas species, cardinals or killifish. And 5.5 is in the higher pH range for some fish. For example Apistogramma pertensis requires a pH of 4.5 to breed successfully.

I would get a vat or something similar and put some peat into it and let it stnad for as long as it takes. You could also use phosphoric acid (call me if you need some).

An RO unit would be very helpful as well

Holger

my job allows me to collect as much RO water as i can handle.I will take some readings and see what they come out like.

just remember r.o water on its own will not give you a true reading

just tested the water and it has come out in the following.
NO3-0
NO2-0
Hardness- 20ppm
Ph-5.8

are the bottles for lowering and raising ph any good?

koinonia wrote:

are the bottles for lowering and raising ph any good?

They work but are a waste of money. To lower your pH use phosphoric acid to raise it you have endless option. Add calcerous rock, filter through clamp shells never mind using magnesium sulphate

You dont need to lower your ph to breed Annulatus. Your ph is fine.
I have bred these repeatedly at a neutral ph and slightly above with no problems.

I am too looking into altering the pH of my water.

Apart from mixing RO or de-ionized water, I have read you can use sulphuric, phosphoric, nitric or citric acid to reduce alkalinity and pH.
The quantities to add depend on your water kH (alkalinity).

1./ Is phosphoric the recommended acid ?
2./ Must the General Hardness (gH) be taken in consideration too?
3./ What is the formula in order to calculate the quantities required for a specific pH, depending on the acid used and its concentration ?
3./ What is the minimum kH to avoid a pH crash?

I am not chemist and would prefer an English reply, not a chemist one !!!

Thanks
Valerie<br><br>Post edited by: Valerie, at: 2007/08/24 09:35

Hi Valerie,
ok, I will try to keep this a non-chemsit answer.
Phosphoric acid is the chemical of choice (it's in all those pH lowering products you can buy in your LFS). It's a fairly week acid. sulphuric, hydrochloric acids are very strong an corosive. Not to be handled if you are not trained to do so. Apart from that they will also increase your water's conductivity.
GH plays no role apart from the KH part of it. There are formulas where you can calculate how much you need but it is easier to go for a bit of trial and error on this one. You won't need much. There is a threshold where a pH crash will occur and it really only takes that one drop. So, take your tap water and let it stand for a day or so, add acid until you reach your desired pH and wait for another day and measure the pH again. It takes a bit of trying but once you know how much acid you have to add it's pretty simple

Holger

makes perfect sense holgar:huh:

Lets say you have a 100L tank siphon out 25L into a beer white plastic continer add phosric acid to the old tank water in small amounts (20 drops equals 1ML) if you get the desired result with say 10 drops (0.5ML) then add in therory 2ml of acid to the display tank, in pratice you would add 75% in one go and the last 25% in much smaller amounts, its a bit like drilling through a 1M wall you use hammer action for the first 90CM the non hammer action for the last 10CM, its a pity in Spain woman divers dont slow down for the last 10CM before always making contact with the bumber of the car they just hit when attemting to park using the same angle of thought.

By using tap water rather than RO water the pH will be more stable, it just means it will take more acid to get to your pH desination, I have personelly use it only on Discus (5.8 pH) it made them much less nervous, as the was less bacteria in the water, the pH is bad news for you bio filter although you could use zeolite to by pass the bio process.

P.S Fish in a 24 hour period can take 1.7PH in the plus direction put only 1.3pH in the negative direction, thats because the blood cant carry the oxygen, that why if you want to do you granny in dont inject wer with baking soda, better to inject her with acid before she signs the new will. The fish wont come to the surface like goldfish do in a bowl, its not that the O2 is not in the water its they cant carry the oxygen in the blood, so be carefully doing the last 10cm drilling through the wall take the hammer action off.

I suspect that sometimes the actual pH is less important to breeding fish than the amount of dissolved solids in the water. The addition of ro/distilled water may be more important that the resulting pH.

I say this in relation to the successful breeding of wild caught Rams where I reduced the tds to 58ppm but the pH remained at 7.2.Three breeding successes made me think that the pH advocated by so many articles I had read was perhaps not the most important factor.

Anyone else have comments on this?


Carl

@Carl,
I agree to some extent. However, in some dwarf cichlids pH is directly responsible for the sex ratio. Nobody wants to end up with 90% males or females.
With some species it does seems to matter.
Apistogramma pertenses will not successfully breed in a pH above 4.8 not matter what the TDS. I have tried. I used pure RO water with a conductivity of around 70 microsiemens and a pH of 6.8. No go. Lowered the pH t0 4.5 with no change in conductivity and they spawned.
On the other hand pH doesn't seem to matter much with Discus as long as you keep conductivity below 150 microsiemens.
Don't know about killis

Don`t forget if you lower your kh to 1 or less it will crash.

at a pH of 4.8 you won't have any carbonate hardness left. Try as you might. That's why it's a hell lot harder to breed some dwarf cichlids than Discus

Intresting topic , I was just wondering has anyone tried the calcium sulphate : magnesium sulphate mix at 3:1 respectively to create their own hardness buffer , I'm in the motions of trying this at the moment as I inject CO2 into my tank and have converted over to Pure RO water. The pH seems to be holding now in around 6.0 at present but thats just with approx 40% RO water in the tank at the mo I really looking to bring the conductivity down so i'm at 190ms now but I'm worried as this gets lower the risk of pH crash gets closer as more RO water is added. I have ordered some Diskus Minerals as recommended by apistodiscus so they haven't been added yet i'm still waiting for it. Also I'm dosing the tank by the pps system for plant growth .
Now i haven't added the buffer to the tank as yet as everything seems to be going ok but i know i will have to do something soon as i can see the effects the pure RO is having almost 4 days into it. I'm getting nervous now and contiplating not going any furture but I'm endeavouring to get the conductivity right down , It a big tank to try and fix if i make an error. I suppose its going to be a very fine balance between CO2, Buffer , RO and plants (make sure they are consuming everything thats going in ) So far so good but the nerves are kicking in the further I go with this. But to date everything is appreciating the way its going fish and plants. Maybe i should stop here ?????? ,

magnesium sulfate is better known as Epsom Salt. It will not buffer your water since it will not raise your kH but only the GH and pH. Baking powder, Calcium Carbonate, will raise your kh and hence buffer your water.

Ah , If its getting too dodgy i'll try the baking powder so .

Don't just pour it in but measure it. 1 degree of German kH(that's the unit the Tetra tests and most others measure in) is equal to .140 mg/l of Calcium or .1 mg/l of Calcium Oxide

Calcium oxide ?? Is it difficult to source? Seems a better way to go 1mg/litre , Its a 900 litre tank I have.

Best way to do this if you don't have access to pure chemicals and I am assuming that you don't, is to take some tank water, say 10 litres and add calcium bicarbonate (aka baking powder). Measure how much you are putting in and how this will influence your carbonate hardness. Once you know how much you will need to get your required carbonate hardness it's very easy to dose it.

If you want to avoid all this messing around get some aquarium minerals. It will tell you on the label how much you have to use to raise your carbonate hardness by 1 degrees. There are various products on the market. Preis Discus Minerals and API RO right come to mind.

I too agree that lowering the Ph to 4.5 is flaunting with DANGER. you have absolutely no margin for error. it only takes a minute swing to send it CRASHING.
Try Peat granuels- Sulphuric acid - almond leaves these three all have the capacity to lower it whilst adding humic acids, Sulphuric as the last resort as this careful monitoring.

Sulphuric acid will also let your conducitivity shot through the roof

Sorry meant Phosphoric acid there will only be a slight increase in TDS,