Extremely high kh and ph...

[tsaraber]

I'm a total newbie when it comes to aquariums. I've spent hours online with google trying to come up with a solution for my aquarium but I'm not having much luck..

Here is the situation. I have a 10 gallon tank, 4 danios and 1 male betta and a few live plants. Ammonia, nitrites, nitrates, most everything I've tested is just fine but the ph isn't so great.. It's at about 8.2 - and the kh is downright terrible, it's about 25 dkh!

I've been using well water that I treat with ph 7.0 Seachem Neutral Regulator but the ph doesn't change (it's soft water). The well water starts out with a ph of about 8.2 and a kh of about 16 dkh.

First question, how on earth did the kh jump from 16 to 25. Is it because of the Seachem? I don't understand why the ph isn't coming down with the use of that stuff unless the kh is causing the problem.

So after doing some research I've decided to give reverse osmosis water a try. I got the water from one of those machines at a local grocery store. The kh on the RO water is 5 dkh, but the ph is off the charts!! And the water is hard.

Right now I have two gallons of it sitting on the kitchen counter, with a bit of the Seachem Neutral Regulator added to it, and it's aerating with just a hose connected to an air pump. At last check the ph was about 7.4 and kh at about 10 dkh.

So my next question - is this ok to use to do a 20% water change on the tank? Is there something I should be adding to it to make it better for the fish? If I do for example, a 10% water change every week with half well water and half RO water, is that good or is there still more I should be adding to the water?

Next question - is the RO water safe to use immediately or does it need to sit for awhile?

Thanks in advance for your help.

 

[jsoong]

The Seachem is just another buffer - so adding it will raise your KH (which is a measure of your total buffering capacity).

Buffers stabalize your pH. Each buffer has a natural association constant (Ka) and will tend to maintain the pH at that constant. Your well water started out with a lot of buffer (which is likely bicarbonates), and will keep the pH there. So unless you remove some of that bicarbonate, or add a LOT more of another buffer, you won't see much of a pH change.

I personally think that removing the extra bicarbonate is the way to lower pH. You do this by mixing some pure water in to dilute it to the desired pH & KH (try 50:50 to start). People use RO water for this. I've never personally tested the parameters of RO water, but it is supposed to have low KH and SOFT, and the pH should be neutual or somewhat acidic. (You shouldn't have to add anything to it.) I wonder if you can try a different source of RO water.

 

[tsaraber]

Thank you so much for your response. I kind of figured that was the reason for the high kh.. I'm going to run to the store this morning and see if I can find another r/o source, or if all else fails I'm going to give distilled water a try. And because I live 20 minutes from any store I'm going to take my test kit with me so I'm not wasting time and money buying 4 gallons of bad water. (I'll just buy the gallon I tested and then move on to the next.. lol)

 

[tsaraber]

YAY! Found better RO water at another store... After letting it sit for a few hours and aerating it the ph is 6.6 and kh, I would say is around 5 but I'm not too sure about that. I just know it's TONS better than what's currently in the aquarium.

So I did a 10% water change using straight RO water. My next question(s) - is it ok to continue using straight RO water until the situation is resolved? Should I be adding anything to the RO water to make it more habitable? Is a 10% change per day too much during this time?

Funny story - I did take some test strips to the store with me so I could test the water. When I got to the checkout, I unloaded the water and I was still holding the strips I used.. Asked the cashier if she had a trashcan. She looks at me, looks at the strips and get's this disgusted look on her face. She thought they were urine test strips. Now what on earth would I be doing with one of those in the middle of a grocery store??? lol

 

[jsoong]

Glad you found better water! This stuff you got sounded much more what RO is supposed to be.

Most people use RO mixed with tap water. Pure RO isn't too good on its own, since it has little or no buffer (KH), you run into problems with pH crash. Some people add salts made specifically for this, but you get the same effect mixing in some of your tap water - cheaper too!

I would mix the RO with tap & find what ratio is right and stick with that with all your water change. With your KH of 16, I say try 50:50, test the result, and go from there. You want your final KH to be around 4-8, and your pH would then be in the 7's.

The trick is to keep pH stable, rather than trying to acheive a magic ideal pH number. So I would try to find a ratio that is easily reproducible so the water is the same with each water change.

I would then SLOWLY change the tank to this new water. 10% a day or every other day sounds about right. Note that with 10% water change, you'll need to do about 40 water changes to completely change the water over - should be plenty slow enough.

 

[Allivymar]

Slightly offtopic, but your response to tsarabear's questions have been really on the mark and easy to understand jsoong. Awesome Have a few kudos!

 

[jsoong]

Oh Allison, you are making me blush!

 

[tsaraber]

jsoong, thank you SO much for your help. From here on out I will do it exactly as you have explained.

I have asked so many local store owners and I have to say I'm not too impressed with the advice any of them gave me. One wanted to know why I was even bothering with testing the kh and when I told him the situation he said the kh wasn't causing the problem and tried to sell me ph down. Another one told me not to use RO water and if I did to definately not use salts in it.

Not hard to see why I'm so confused. We've had two chinese algae eaters die in the past couple of months and I'd like to get the water in better shape before we try adding another.

Thanks again!!!

 

[Allivymar]

Unfortunately, some lfs owners aren't exactly a wellspring of knowledge. We're lucky to have some on this forum who are (Bernie, Terry for example; there are a bunch more) but I have found guys like this few n far between outside the forum.

Then again, many pet store owners aren't fish folk; they are selling a variety of animals and unfortunately they don't make a lot of money off fish (their money is made off the additional products and hardware). So many of em don't expend a lot of energy on research as thats not where the money is. Plus, they ARE in the biz of making money; if they aren't fish folk its easier to tell you to just buy something instead of suggesting something that they won't make money off of.

 

[jsoong]

Also, the Lfs had to make some money too. They won't do too well just telling you to use something for free (like heat or salt for ich). They would rather try to sell you potions & lotions....

tsaraber - noticed you are going to get chinese algae eater for your 10 gal tank. Ok I am no tropical expert (goldies person myself), but I know CAE's grow too big for a small tank. Although they are cute when small, they get UGLY when grown up, plus they are terrible algae eaters. A better alternative would be the siamese algae eater. <OK tropical experts, you can correct me if I am wrong! >

Hope this helps.

 

[tsaraber]

You're both right about the LFS owners - They do have to make a living too I suppose.

jsoong - I'm not sure if what we had was a chinese or a siamese algae eater. I've looked up photos and depending on the photo they both look like what we had. The LFS owner told us it would get to about 6 inches (again getting mixed info on the net regarding the max size of both fish).. I guess even 6 inches is too big for a 10 gallon tank. Whatever we had it did a wonderful job cleaning up the tank. I shall have to look for another alternative to cleaning up the algae.

In the meantime I'm not having any luck at all mixing the RO and tap water. I started out with 50/50 (one gallon of each) in a 10 gallon bucket, and I'm aerating it with just the air pump and one of those bubble curtains (yeah beginner, don't have any fancy stuff).. Well after a few hours the KH and PH was still really high. So I started adding more RO water until I had eventually added another entire gallon. Still the PH was high, the KH though was down to 8 by this time so at least something was working.

Out of curiousity I tested the plain RO water again - the PH was sky high!! Not sure what happened overnight because when I brought that water home it was fine but all of a sudden the PH shot up - guessing it has something to do with the oxygen leaving the water? No idea. The tap water actually comes out of the faucet neutral but again, after a few hours without any aeration the PH shoots up.

Anyway - I shut off the air pump over night, covered up the bucket and then this morning I checked the ph and it was at 7.8.. I didn't bother checking the kh - at this point I've pretty much decided this batch of water is a loss anyway, why waste the test solution. But just for kicks I added some PH Down that I had sitting around from back in the beginning when I actually thought it might be useful.

I think I'm out of sources for RO water, I haven't seen a machine anywhere other than the places I've already checked. I'm thinking maybe I'll give distilled water a try but you know, at this point I'm just about to give up hope.

 

[jsoong]

Hm ... interesting problem with your water.

I can hazzad a pretty good guess on why your tap water's pH changed. It has got to do with CO2, pretty common in well water. There is a fixed relationship between bicarbonates, CO2, and pH. If you want more details, try this:
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

Anyway, with your tap water's KH at 16, the pH would have to be pretty high, assuming normal atmosperic CO2 level (0.03%). The fact that the pH was neutual, means that there is excess CO2 in the water. (One other possibility is that there is something other than bicarbonates in the water contributing to KH, eg phosphates, or nitrates). As I say beforen high CO2 is quite common in well water. The CO2 keeps the pH down, but once it leaves the water, the pH shoots up - what you are seeing.

I am not sure what is happening with the RO water. One thing to note is that a lot of supermarket's water machine is filtered water, not RO, so will have the same characteristics as your local water. In RO water, the water is drawn through a semi-permeable membrane, & the ions - Calcium, bicarbonates, etc. is left behind. You should have more or less pure water (but not quite as good as distilled).

Your RO water had initial pH of 6.5 & KH of 5? If the pH is 6.5, and the CO2 is atmospheric, the KH has to be less than 0.5. (Again, assuming all the KH is bicarbonates). If your KH reading is true, then I have to conclude that there is high CO2 in that water too, and it will do the same as your tap water - off gas & rising pH.

However, with a KH of 5, the water should stabalize at pH of 7.4 or so, not off the scale... :? That mix down to KH of 8 should have been fine. AT atmospheric CO2, the pH should stabalize out at 7.8 or so, without pHDown or anything else.

At this point, I have a few of suggestions:
1. I am assuming that your local water has high CO2, and the RO machines won't get rid of that, so you will not get a true pH reading until the water off-gas (in 24 HRs). In that case I might try to use the water with the lowest KH as a mix, or distilled water (although that is expensive). BTW, for testing, you don't need gallons of the stuff, you can just mix up a cup or two. You'll have to wait overnight to get a true pH reading after a mix though, so that would try your patience.

2. You can remove the high KH in your tap water by adding acid. Acid (H+) & bicarbonates makes CO2, and that can be removed by aearation. People filter the water through peat moss in this method. (The peat adds tannic acid.) I've never done this so I can't tell you how much peat to use, how fast to filter the water, etc.

3. You can leave the pH alone, and find fish that will do well in hard water & high pH.

That's all I can say right now. Sorry to be so long winded & technical. Maybe there are water experts out there that can add more useful advice?

 

[jsoong]

About the Chinese vs Siamese algeae eater .. Again I must stress that I am no expert. However, the Chinese is supposed to grow to a foot or more, and when it gets bigger, it loses the nice red colouring, and stop eating algae, and start eating fish!

Apart from the Siamese algae eater, others to consider are Oto cats or cory cats. People at the forum seems to like them & they don't grow too big. However, I am not sure of their pH requirments.

One more thing to add on the water issue - you can also drop the pH by adding CO2. There're tons on info over at the Plant forum if you are interested.

 

[ScottS]

Hmmm RO water with a dkh of 5? Odd. Anyhow, my tap is just about the EXACT same as mine. I have Cardinal Tetras, so I really try to soften up my water. I use 3:1 of RO water to tap. That gets me down to about 6-7 in hardness. You have really hard water, but you have pretty hardy fish, so 3:1 may be extreme for you. I just set up my own little chem lab in the kitchen one evening and experimented with the end reults of mixing RO to tap at different ratios.

Oh yes, and definitely skip those Chinese Algae Eaters!

 

[tsaraber]

Noooo don't apologize Jsoong, I really appreciate your long winded & technical answers.

I should clarify a bit, as I accidentally gave you a bit of misleading information.. I was using well water previously. I was driving to my step-father's house and borrowing his water.. But for the tests I've been doing this week I decided to use my own tap water, which is city water. The quality of his well and my tap water is really pretty similar which surprised me. The kh of my tap is slightly higher but I believe I ended up with pretty much the same high ph from them both after the water sat for awhile. (maybe not exactly the same, but both were too high).. I started using his well water because he has a water softener and back then I was under the impression that using the soft water would allow me to lower the ph. Of course when it didn't work I started doing more research and found out that it was the KH I should have been looking at.

So that being said I should also mention that I live in the middle of nowhere, but we are on local city water - The RO water is coming from cities 20 miles away that aren't on the same water source. I have no idea what the water looks like before it goes through the RO process but I intend to find out just for kicks.

Now as for the KH reading - it could very well be that I'm doing it wrong. The instructions say to count the drops of solution you add to the test tube until the water turns bright yellow. Well bright yellow usually takes 3-5 drops but it does turn a real light yellow right away with the first drop. Wasn't sure if I should count that or not.

I picked up some distilled water today. The expense doesn't bother me so much since it's only a 10 gallon tank (anything bigger and I can see the distilled water no longer being an option).. The distilled water is extremely acidic and the KH is between 0-3 (3 drops to bright yellow, see above). I'm going to let it sit in the bucket until later tonight and test it again but if the ph stays the same, which I'm expecting it will, I will add my tap water and go from there like you suggested earlier.

But your information has been extremely useful. Thank you again for all your help.

 

[Allivymar]

Some pics of True SAE and False SAE here so you can compare : http://www.azgardens.com/algae_eating_fish.php

 

[tsaraber]

Two new posts while I was busy babbeling.. lol

Thanks for the recommendations on fish Jsoong - had spotten the Oto Cat during a google search earlier. That one looks promising. And I've been looking into the CO2 deal as well - considering the tank is sparsley planted I know it would be a good idea. Definately going to pay a visit to the GOOD LFS (ok, not so local, it's an hour drive) this weekend and see what I can dig up. I'm wondering if KH matters to CO2..

Thanks for your input too ScottS.. I've got my own little chem lab setup in the kitchen as well. Even cleaned out an entire cabinet to store all the fish stuff. lol I'm going to go start mixing in the tap water a little at a time until I get some results I'm happy with.

Ohh great link Allivymar.. I've determined I did have a Chinese algae eater, wasn't an SAE after seeing those pics. I also have a nice place to get started checking on C02 systems..

 

[jsoong]

Lots of city water comes from wells too. And I wounldn't be surprised if all the water tested the same - towns in an area all tend to tap into the same aquafier.

KH & CO2 ....

First, you need to make sure that KH is actually measuring bicarbonate levels. Although KH (Carbonate Hardness) would implied that carbonates is what it is measuring, most test kits cannot tell bicarb from other buffers. (Some people call this test Alkalinity instead to be clear). To tell if you have other buffer, you measure the pH and KH after water had equilibrate to room air. Then you plug the numbers into the Henderson-Hasselbach equation & see if it match. The pH & KH number should give you atmospheric CO2 of 3 ppm. If not, you do not have a pure bicarbonate buffering system and you cannot use any of the CO2/KH/pH tables around.

Second, a certain amount of CO2 retained in the tank will cause a fixed drop in pH. Eg. increasing the CO2 10 times (from 3 to 30) will cause a 1 point drop in pH. Now, if your KH is 0, making your starting pH 6 (or so), dropping by 1 (to pH 5) is not good. But if your KH is 10, making your starting pH 8'ish, then it would be OK to drop the pH.

Note there is a simplification used in the second point. I am ignoring the HCO3 formed during CO2 injection. If you have a resonable HCO3 level, this is a small error. But if your KH is 0, it is not & there will be a large error introduced. (Note that the CO2/KH/pH tables I've seen all use this simplification - so you can't use the tables if your KH is less than 1 also).

 

[tsaraber]

As usual, thanks Jsoong.. =) Lots of information to look into.

I haven't had much time so far but I'm still playing with the distilled water / tap water combo. What I came up with today so far is that 1 cup of tap water and 7 cups of distilled water give me a ph of 7.2.... I didn't test the kh yet - I want to wait until the morning and then test the ph and kh both after the water has had time to sit awhile..

So what I'm wondering now, is this mix ok to use in the tank? Is just one cup of tap water to the 7 cups of distilled water going to add the necessary trace elements and such that the fish require? I know that I need to test the kh first and make sure that's decent before I can make any true decision on the water. But I was curious about the ratio.

I did pick up some Seachem Equilibrium but if possible I think I'd feel better mixing the tap water instead.

 

[jsoong]

A 7:1 mix! Wow. You must really have hard water.

Let me take a guess. I predict that the KH of the mix will be 1.5 to 2.

Is that good or bad? Depends on the fish / plant you intend to keep. Some fish do require that low a pH /KH. If you are sticking with the betta & Danios, I think that would be a bit extreme. You might consider KH in the 4-6 range, (or a pH around 7.4) A bit more KH would keep the pH more stable. If you are going to do CO2 injection, I would go even higher on the KH/pH yet.

For KH of 4-6, I would predict a 3 to 1 mix would be good. Of cause, you'll have to test it to be sure.