Changing your pH

First off, I am not advocating changing your ph level for any reason other than a necessity... ie you have fish or plants that REQUIRE it to survive, most fish WILL acclimate to a good range of ph anywhere from 6 to 8.

What you need to understand first is what affects ph in your water... the main thing is the waters buffering capacity, this means your waters hardness (mineral content) there seems to be a lot of confusion that a low pH means soft water and a high pH means hard water.. this is NOT true. Hard water means a high buffering capacity (mineral content), and in reverse low buffering capacity means soft water. How does this affect pH?, simple if you have hard water the buffering capacity of the water is going to keep your pH HIGH... if you have soft water then there are less buffers and your pH will be LOW. Now, as far as using chemicals to LOWER your pH... this does not work with hard water, because you still have a high buffering capacity, so what happens is your pH level drops because of the acids in the pH lowering addtives... but shortly after your pH is going to spike, usually all the way back up to where it was before because you have hard water. This is VERY hard on your fish and will almost certainly result in death if done repeatedly to counter the effects of the pH going back up.

There are a few ways to safely LOWER your pH

1. Use driftwood or peat moss in your tank, this will slowly release acids that lower your pH gradually, however with hard water you will have to replace the peat moss regularly or it will go back up... this also applies to driftwood as the tannic acid levels drop the pH will go back up, but most likely you are not going to keep replacing driftwood due to cost.

2. Use a mixture of distilled or R.O. (Reverse Osmosis) water to dilute your main water source.... this will reduce the buffering capacity (mineral content) of your water, thus your pH will drop as well. A word of caution on this method... you MUST keep a safe hardness level with this, you CANNOT use 100% distilled or R.O. water, this will make your pH very unstable because of the lack of buffering capacity. You ideally need a hardness test for GH and KH levels to make sure when you dilute your main water that it still has a sufficient buffering capacity to keep the pH stable.

3. If you use method 2 properly then you can further dial in your pH level with the use of driftwood, peat moss or even live plants. Now that your buffering capacity is lower it will be easier to adjust it to the exact level you want, but it can still be tricky because you will need to monitor the pH so that it doesnt drop too fast or too low.

EDIT: Please note that you should still take care when using peat moss, as I mentioned before, you will have some ph swings if you use it in the tank and dont monitor the ph levels frequently.... Sirdarksol mentions a safer alternative to using in tank peat moss in his post below, and thank you for the advice SDS =)

On to RAISING your pH

This is much simpler to do and most people dont even have this problem, simply adding crushed coral or certain rocks (such as limestone) that leach out minerals will raise your hardness and buffering capacity, which will result in a higher pH level. I do not recommend using pH raising products, these will cause pH swings much like the pH lowering products do.


I hope this helps everyone with better understanding hard water versus soft water and how it affects your pH levels.... also in closing keep in mind that regular weekly water changes and maintenance go a long way in keeping your pH level and buffering capacity stable!

 

Actually with pH, low is acid high is alkaline...

 

I know that, I never said anything about it because thats not what the topic was about, its about water hardness and how it affects ph and how to change your ph the proper way.

 

lol was replying to someone else who had tried to correct you... but that seems to be gone now. Weird. Sorry for the confusion!

 

Lol sorry then, nevermind what I said in response... yes low ph is acidic and high ph is alkaline =)

 

Sounds good Clinton. The only thing I would add is that limestone is one of the rocks that will raise PH but it does it very slowly which is a good thing.
Carol

 

Looks pretty good.
There are two issues I have with this:
First of all, you paint with pretty broad strokes when you say "hard water does not mean high pH." While this is technically correct, it is very infrequent that you will find municipal water that has one without the other. In general, the presence of minerals that raise the hardness of the water also raise the pH (this is because, for many water supplies, limestone is the source of the hardness. As was stated, limestone is also useful for raising pH).

Second, I would not suggest using peat directly in the tank to raise/lower the pH. It provides a roller-coaster ride similar to what chemicals do (though slower, because the leaching of tannins is a little slower). The best way I've heard of to use peat to adjust the pH is to make the peat water ahead of time. Fill a pillowcase with peat moss, toss it in a garbage can with your water supply and an air stone, and let it steep for the week before doing a water change. Then you can mix regular water and the peat water until you get the pH you want in your tank, and use that with your water changes.

 

First, I think you misread the first thing backwards... I said high ph doesnt mean hard water, high buffering capacity equals hard water, which does affect ph as I stated making it higher, but its not the ph that makes the water hard =)

Second, you are right about the peat moss... and I also mentioned that peat moss would only lower the ph until the acids were leached out and that you would need to replace it to keep the levels stable or else it would go back up, and I agree with you that it is by no means a great way to go unless you monitor the ph closely or go with the method you suggested which would be the safest.

 

It goes both ways, because the common source of high pH is often the limestone, which means high buffer.
I was saying that they usually go hand-in-hand in municipal water supplies. You can artificially make water with a high pH and little buffer, but it doesn't happen very often in nature, at least that I've seen or heard about.

And, we should reiterate, with this discussion, that the ideal method is still leave your pH alone. ;D

 

Yep thats what the very first paragraph of this thread states =)


And thats what I meant by the high ph, artificially creating a high level doesnt mean that you have hard water, just like artificially creating a low ph doesnt mean you have soft water =)

 

I know, that's why I said, "reiterate." I just wanted to make sure we said it again, because sometimes people get so caught up in reading the end of the discussion that they forget about the original post (and sometimes they do the opposite), and I didn't want people going through all the trouble of setting up a garbage can of peat moss when they didn't really need to.

 

I completely understand lol, kind of like skipping to the end of a book just to get the good parts!

 

other than limestone what is another safe way to raise ph?

 

Any type of calcium substrate, such as crushed coral, will add buffers to the water to allow the ph to be higher. Its basically a mineral content problem, if you have soft water then you have low mineral content, low minerals means you have a low buffering capacity... which means the pH will be low.

 

This is great information on what, for me, has been a confusing subject. I think I'm finally starting to understand the connection between hardness and ph.

I'm having a difficult time interpreting the results from the API gh and kh test kit.

On the kh test, the first drop turns the water a slight yellow/orange color and the more I add the more orange it gets. The instructions say to add drops till the water in the tube turns from blue to yellow and I'm never seeing any blue at all.

The gh test turns green after 15 drops.

I can't figure out how to use the chart in the instructions. There is only one chart. The first column has the number of drops and the last has the results (I guess) listed as kh and gh. So is my kh/gh 17.9 (1 drop) or is my kh/gh higher than 214.8 (the chart only goes to 12 and I used 15)?

I know my city water is very hard and has high ph. My tap water ph is 8.8 on the api high range ph test from the master test kit.

I'd appreciate any help on testing my water hardness because though I'm normally a somewhat intelligent person, testing for hardness clearly is like rocket science to me. lol I am using diy co2 made from two 2-liter bottles with the diffuser that came with the Hagor co2 that uses the prepackaged yeast packets. I want to figure out how to use the water hardness test so I can calculate the amount of co2 I'm adding.


My tank has been set up since Christmas. I have driftwod in the tank and a filter bag with peat moss in my canister filter. I try to be consistent with small weekly water changes to avoid big ph fluctuations. When I refill my tank during water changes I fill a container and add declorinator to that and then use the intake on the filter to fill the tank from the container. My thinking is that the water is passing over the peat moss on the way into the tank helping to lower it's ph on the way in. I have several pairs of angels that breed consistantly. Is that an indication that the water is OK?

My ph readings are always 6 to 6.6. Usually 6. It does not shoot up after a water change. I wonder though, when I'm getting a reading of 6 if the ph could be fluctuating under 6 because that is as low as the test goes.

75 gallon with live plants, 13 angelfish, 10 rummy nose tetras, 6 corydoras, 6 oto cats, 3 lamp eye tetras and sometimes a pleco. Penguin 330, marineland c series 220 with carbon and peat moss.
API freshwater Master test kit
API gh/kh water hardness test
ph 6
Amonia 0
Nitrate between 5.0 and 10
Nitrite 0

 

GH and KH levels are usually fairly close to the same, so if your GH level is 200 or higher then your KH is probably around the same range (maybe a little lower)

At any rate it sounds like your GH and KH levels are fine considering the pH of you tapwater and that you already stated that it is known to be hard water, I would say your pH level of 6 is a combination of...

1. live plants which are using minerals from the water for growth (which is another reason you should add fertilizer for live plants)

2. the driftwood and peat moss leaching acids into the water

3. regular waste accumulation that naturally lowers ph

4. the addition of co2, which directly affects ph as well

You may be going a little overboard with the peat moss, especially since your pH is so dangerously low.... take the peat moss out and test the water periodically to see if this helps. Also remember to do gravel vacs at least once or twice a month to remove excess waste, which can also lower your pH.

 

Thank you Clinton1621!
I appreciate your help on the hardness test. I don't know why I'm having such a hard time using that thing.

I'll take your advice on the peat moss and pull it out this weekend when I do a water change and clean the filter. I use a gravel vac each time I change the water. I try to do a water change each weekend to keep things consistent.

I'm also planning to pull out the carbon after spending some time on the forums here reading about it leaching toxins back into the water.

Thank you for explaining about the plants and fish waste lowering the ph, I was not aware of that so its good to know. I wish the ph test was capable of measuring ph lower than 6 so I'd know where I'm at. I noticed that the ph meters that clip in the tank with a suction cup go down to 5.2 so I'm going to pick up one of those to see if my ph is actually less than 6. Hopefully they are more accurate than testing strips which are useless.

I thought people that have Discus keep their ph at like 4 or 5 or something so there must be test available that go that low.

 

Heres a thread I have for filter care that you might like to check out...

https://www.fishlore.com/fishforum/filters-filtration/29341-filter-maintenance.html

 

Lol that's the thread I was referring to that I read last night. I didn't notice that you wrote that too. Your a busy guy. And a night owl too it looks like.

Well all my tanks are officially carbon and peat moss free. I'm a little skeptical about the carbon, its hard to change something you have done forever. Reminds me of hearing how bad UGFs are. Couldn't imagine a tank without an UGF till I took them out and saw how detrimental they were. Hopefully I'll have a similar experience taking out the carbon.

 

Lol, yep I work second shift, so I am definitely a night owl. I used to use carbon all the time myself, until I researched it and found out that it does more harm than good. I dont think the leaching is really a major problem though, it doesnt leach out anything that wasnt in the tank to start with... and it would have to be in the tank for over a month before it started to leach, as the carbon dissolving and breaking down with age is really what the "leaching" actually refers to.

The main issue is really that it doesnt discriminate what its removing. So it actually removes all the good minerals and metals that the fish and live plants (if you have plants) need to be healthy. It will also remove fertilizers (which are minerals and metals) that you add to help the plants grow... so why would you want to remove something that you paid money for and then have your plants all start to die lol. The removal of trace minerals can also lead to mineral defficiency in your fish, and or poor osmo-regulation (how fish absorb and release water)... so once again why would you want to possibly make your fish mineral defficient if you dont have to?

Carbon does have its good qualities, like removing meds from the water after you use them... but even this can be done without the use of carbon, simply change all the water and voila, no more meds!