Water hardness, Discus    2/17/08
Hi. how are you? It's me again. I just wanted to know what is the approximate hardness for discus. Your articles said about 10 degrees GH. Is this the same as 10 degrees dh? Thank you for your help.
<Please read this article before you do anything else:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
If you don't 100% understand water chemistry, then don't start adjusting the water chemistry in your aquarium. Instead, do a water test on your tap water, and then choose fish that are adapted to those conditions. If your local water is hard, then stick with hard water fish. In any event, there's no such thing as "10 degrees GH" which is why I'm warning you to be careful. I'm guessing you mean "10 degrees dH" which is sometimes referred to as the 'General Hardness', hence 'GH'. But the scale itself is in units dH, which stands for Deutsche Haerte, or 'German Hardness'. Discus vary in their optimal water hardness requirements. Wild-caught fish will need water that is quite soft, ideally 3-10 degrees dH. Tank-bred fish are less fussy, and will do well at up to 15 degrees dH, maybe even slightly more. But regardless of the water hardness, the Discus need water chemistry stability, and that means that you understand -- and can manage -- the Carbonate Hardness of the water (measured in degrees KH). Cheers, Neale.>

Soft Water Tank-- Which Water Is Okay  2/15/08
Hello!
<Hi there Mich>
I was wondering if you could help me out. I have set up a soft water tank for cardinals and Corys and such and mix my hard Los Angeles tap water with the RO water.
<Good technique>
My RO unit filter has sprung a leak, and after a lot of phone calls and taking time off of work to be home for it to be fixed... no one has been able to fix it.
<Mmm, try to find the actual manufacturer... should be written, embossed on the component/s... and contact them (the Net), looking for the replacement part/s>
This is starting to look like it will take awhile to sort out since no has been able to fix it and my work schedule is so high I can't put any more time into searching for someone to repair it right now.
<If it's very old (one of mine was recently...) it may be best/time to replace it entirely>
My question is, which water is safe to buy from the supermarket to mix with my water. I know when you go down the bottle watered aisle some are okay to use, and some are not.
<The simple, cheapest (likely outdoor vending machine) RO or RO blend>
I don't want my fish to be negatively affected while I am working out the RO situation.
Thanks for your help!
Michelle
<Welcome. Bob Fenner>

Adapting, FW, fish, water cond.s... e.g. Discus and hard water   2-9-08
Hi again. I just wanted to know, is it possible for a fish to adapt to a certain water condition? For example, a discus adapting to a slightly hard water. Thank you.
<Up to a point, yes, fish will adapt to a range of water chemistry conditions. But the degree to which this is true depends profoundly on the species in question. Guppies won't adapt to soft/acid water, for example, even though they will do well in hard water, brackish water, and if acclimated carefully, even seawater. Wild-caught Discus simply must be kept in at least somewhat soft, slightly acidic water (i.e., pH 6-6.5, 3-5 degrees dH). Tank-bred Discus are a bit more amenable to harder water, and will do well at pH 7, 10 degrees dH. Given that Discus need much warmer water than most other tropical fish, and are also that bit more sensitive to bullying and nitrate poisoning, there's no point keeping Discus in a "community" setting, so you may as well set up the one tank just for them with precisely controlled water chemistry. Cheers, Neale.>

Re: water hardness     2/16/08
Hi, I am sooo sorry to bother you once more. My fiancée and I had to do something. Anyway, I wanted to know, is gH 4 considered hard or soft? I am so sorry to bother you Dr. Fenner and everyone else. Please forgive me. Thank you once again.
<Please read this article:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
In the section 'General hardness: the dH scale' you'll see a table where you can translate 4 degrees dH (which is surely what you mean by "gH 4") into a subjective statement of hardness. In your case, the water is quite soft. Do make sure you understand that hardness matters, and you won't be able to keep all tropical fish at this particular water hardness. Livebearers, for example, will do badly in soft water. Cheers, Neale.>

Re: water hardness     2/16/08
Hi again, I just wanted to know, what are some methods of lowering water hardness? Do driftwood and plants lower hardness?
<No. Please do read this article:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
Questions of this sort indicate that your understanding of water chemistry is extremely hazy. Inexperienced aquarists should NEVER alter water chemistry. Instead, buy fish suited to your ambient water chemistry. Since you have no idea how water chemistry works or how to change it, any changes you make will likely be unstable and rapid, which will cause problems for your fish. Cheers, Neale.>

African Cichlid GH Too High  12/12/07
Hello Neale.
Sorry for bothering you again. I am still in the first week of cycling my Mbuna tank. My water parameters are (Test Kits from NT Labs UK) - pH 8.1, KH 9, GH 25, NO2 1, NO3 5, NH3 0. How can I lower my GH? Should I use RO/DI water?
Thanks you
Ghulam
<Hi Ghulam. Don't bother... GH 25, KH 9 is perfect for Rift Valley cichlids. They will love it. The nitrite is still a bit high though, so be diligent with water changes, and don't add to many fish too quickly! Cheers, Neale.>

Re: Cichlids GH Too High, Africans  12/20/07
Hi Again Neale.
I am now in my 18th day of cycling my Malawi Cichlids tank (Mbuna) and last week my GH was 25, now its 28. I tested my tap water and its 7 GH. Is it still ok for my future fish? Will they breed in these conditions? What can I do if I need to lower it?
Help
Thanks in advance :-)
Ghulam
<Greetings. Malawi cichlids are fine at 25 degrees dH general hardness. On the other hand, if your tap water has a hardness of 7 degrees dH and that rockets up to 25 degrees in the aquarium, then you don't have much water chemistry stability. While it is fine to use calcium-rich substrates in a tank to harden the water, if you're going to go down that avenue, it's best to perform small but frequent water changes. Perhaps two 25% water changes each week. So test the hardness before the water change, immediately after the water change, and then seven days after the water change. If the hardness variation is small (say, between 20 and 25 dH) then don't worry too much. But if the variation is between 10 and 25 dH, that's less good, and you'll want to do smaller water changes but more often. With Malawi cichlids, hardness and pH don't matter too much in terms of exact values, but what does matter is stability. By the way, note "GH" is what you're measuring, General Hardness, and not the scale used, which is "dH", or "Deutsche Härte", literally "German Hardness" in German. One other thing I'd remind you: carbonate hardness ( degrees KH) is somewhat more important with Malawi cichlids than most other aquarium fish. You want a consistent KH of at least 7 degrees and ideally more than 10 degrees KH. Carbonate hardness is the thing that keeps pH steady. Again, anything between 7.5 and 8.5 will suit these fish in absolute terms, but what they hate is dramatic variation, so if you run the tank at pH 8.0 (a good number) then you want to keep variations small, say between 7.8 and 8.2. The tendency will be for the pH to drop across the week, and the water changes will bring the pH back up. A high carbonate hardness inhibits this pH drop; the higher the KH value, the smaller the pH fluctuation. Do also remember if you plan on breeding your Malawi cichlids, then you have to ensure none of the fish can hybridise, and that there are enough females per male to prevent bullying: when groups of one male and one female are kept, the female can be battered to death long before she has any babies! Cheers, Neale.>

Very soft water and Neutral Regulator? 12/07/2007
Hello,
<Ave!>
First time emailing you, but a long time reader.
<I feel like a host on drive-time radio: "First time caller!".>
I have to say, your site has got to be the best and most comprehensive aquaria site on the web.
It's awesome plain and simple.
<Glad you like.>
I've read all the FAQs and think I pretty much understand the roles of buffers and PH in the water. I do still have one question though. The water here in my area of Georgia is very soft. Out of the tap and after sitting a little while, it has PH of 6.8 and the KH and GH both read as 1dh.
<Definitely on the soft side. While great for a lot of fish in terms of matching "the wild", you will need to raise the KH a bit just to get stable conditions.>
I set up a 30 gallon community tank with (1 small Bala to be moved into a 90 gal soon, 1 dwarf Gourami, 2 small silver dollars, and a few Neons) a couple of months ago and started just using dechlorinated tap water during the cycling. Making about 1/3 tank water changes almost daily I still noticed the PH in the tank kept dropping lower so I bought some SeaChem Neutral Regulator and started using it by doctoring the tank (bad Idea as it made the PH jump from 6.5ish to 7.0 in seconds) and then doctoring each batch of new water going into the tank.
<Yes, do always treat water first, then add to tank.>
Once the tank cycled I started watching the Nitrates and not doing as frequent of water changes but still doing about 1/3 each weekend. The PH was staying right at about 7.0, KH was about 4 and GH was about 6 so I was happy enough.
<All sounds good.>
After a trip caused me to miss one of my weekend water changes and still having very low nitrates I decided to see what the tank would be like, nitrate wise, after two weeks. After the two weeks the Nitrates were still low but I checked the PH and it was down around 6.0. My test kit only goes to 6.0 so I'm not sure if it might have actually been lower.
<Ah, a pH crash. All tanks become acidic over time, but the rate depends (mostly) on the carbonate hardness (KH) because that's the prime source of alkalinity, i.e., stuff that neutralises acids.>
Now that may be too much background for this simple question, but I really like the posts from people that include a lot of background because I find it easier to apply to my situation. So, on to the question.
<Yep...?>
Do buffers like SeaChem Neutral Regular dissipate or become less effective over a small amount of time?
<All, repeat all, alkalinity gets used up in an aquarium. What matters is how rapidly the tank is acidifying, and how much alkalinity you are adding. Think of alkalinity as money in your bank account, and acidity as how much you spend, and water changes as your salary that tops up your bank account at fixed intervals. If your bank account contains only a little cash, your expenses will quickly exhaust your savings before pay day. But if you have lots of credit in the bank account, then your expenses won't reduce it to zero before pay day. Likewise, if you have a heavily stocked tank with a low level of alkalinity (e.g., a KH of 3 degrees) then the acids will quickly "use up" the alkalinity in the water, and once that happens, the pH will start dropping until you do a water change to raise the alkalinity back up again. If you're somewhere like Southern England where the KH of the water can be 15 degrees right out the tap, then the alkalinity is so high that even in a heavily stocked tank, the acidity will never get a chance to use up that alkalinity between water changes. Aquarists in Southern England might not have the perfect pH for soft water fish (it's around 8.0) but that pH is at least very, very stable. On the whole, fish care rather more about STABILITY than the precise pH, so finding a way to keep the pH stable is more important that trying to pick some arbitrary value you think might be better, only to have it bounce up and down between water changes.>
I use a gravel vac at each water change and have an UGF so I can look up at the bottom of the tank with a flashlight and there's no accumulation of detritus at this point. There's nothing in the tank that should be lowering the PH as I have fake rocks and plants. There is a piece of driftwood but it has been in a tank for the better part of 10 years so I wouldn't expect that to be the problem, would it?
<Wood can easily reduce pH, even after 10 years. Partly, it's simply decay of organic material, and not just the better known "tannins" produce by wood (the stuff that makes water brown). Try this experiment: put the wood in a bucket of water overnight. If the water is brown the next day, it's still producing tannins. Nitrate is another source of acidity (turning into nitric acid in water). There's really lots of sources of acidity in aquaria. Focusing on any one source is a bit of waste of time. Instead, take an holistic approach, monitor the pH changes, and raise the alkalinity (by raising the KH) to keep the pH stable.>
At this point I was considering adding some seashells or crushed coral to my canister to see if that along with the NR would help.
<Yep, this works well. If you raise the pH to 7.5, and the KH to 5 degrees or so, your standard issue aquarium fish will be fine. Even Neons! More Neons die from Neon Tetra Disease, heat exhaustion, or being eaten by Angelfish than ever die from hard water, and yet everyone thinks they need very soft water to thrive. To breed, yes, but simply to school about happily, they're fine in most anything.>
I also read about using plaster of Paris pucks as long as they were only limestone and gypsum, but wasn't sure about that approach.
<Don't like this at all. Go with crushed oyster shells or crushed coral. Half a cupful in a canister filter should work fine. Place in a media bag (or even the foot from an old pair of pantyhose). Monitor the pH and KH over the next few weeks, and then add or remove the shell/coral as required. It's a bit trial and error because in part it depends on how much you crush the shell/coral, but it is at least cheap and effective. Do also remember that once covered in slime, this media will stop dissolving, so regular cleaning is important. Maybe replace the stuff every 6-12 months, too.>
I tried adding some baking soda to a
separate container just to experiment, but the PH in that container shot way
up to around 8.2-ish. Didn't want to use that in my tank.
<You can use a home-brew Malawi salt mix for precisely this thing. A common Rift Valley salt mix is as follows. For 5 gallons/20 litres of Malawi-like water, the mix is:
* 1 teaspoon baking soda (sodium bicarbonate)
* 1 tablespoon Epsom salt (magnesium sulfate)
* 1 teaspoon marine salt mix (sodium chloride + trace elements)
Stir in the bucket, and then when dissolved, add to the aquarium. Since you don't want the full strength stuff, maybe use only a 25% dosage (i.e., cut the amounts down to one-quarter the listed amounts). Always remember to do water chemistry changes slowly. In this case, water change 25% of the tank with the hardened water and see what happens. Do another 25% a few days later if all is well. What you're aiming for is something with a reasonable amount of KH and a pH that stays stable from week to week. The precise pH doesn't matter, so long as it is somewhere between 6 and 8. What must happen is that it stays there. If the pH drops from 7 to 6 in a week, that's not good. But if it 7.5 on Monday and 7.5 the following Sunday, that's very good, even if the pH sounds "too high" for your fish (it isn't).>
I guess I'm just trying to figure out the longevity of something like Neutral Regulator in my tank and maybe an additional and less expensive way of supplementing that. I'd like to get the 30gallon worked out before I set up my 90gallon.
<I suspect once you've hit on how much of the Malawi Salt mix to use, or how much oyster shell to leave in the filter, you'll be laughing.>
Thanks in advance for any insight you may have and see you around the FAQs.
Lynn
<Good luck, Neale.>

Re: My story and questions... FW Hardness... expl.   11/28/2007
Howdy Neale,
<Andrew,>
I'm very sorry to bother you again, but I got a few things on my mind.
Since the last time we talked, I have added two new internal power filters to my 55 gallon tank, and relocated a lot of my fish to new homes.
<Cool. I'm sure this is the right thing to do.>
Anyhow, I remembered you asking me what my water harness was due to it directly relating to osmoregulation. I was reading on the article about PH and water hardness from Bob Fenner on WWM and it got me kinda confused.
<Oh?>
From what my understanding is, plain and simple English, KH is the waters capability of buffering and maintaining a stable PH. Is this correct?
<Yes and no. Let's start with the terminology. "KH" is the scale, like "Celsius" or "metres". KH is used as a scale for carbonate hardness. One degree of KH means there are as many carbonate and bicarbonate ions in the water as if there was 17.8 milligrams of Calcium carbonate dissolved into the water. So, KH is a scale used to describe the amount of carbonate and bicarbonate in the water, as opposed to general hardness (measured in degrees dH) which is calcium oxide concentration, and salinity, which is sodium chloride concentration. They're all similar but different. All three describe the mineral content of water, but only the carbonate/bicarbonate ions have a substantial impact on pH. That's why you need to measure KH when you're looking to stabilise the pH. Salinity doesn't buffer the aquarium at all, and general hardness salts to only a very limited degree.>
As for GH, this is the value for the amount of minerals in the water. Seems ok or am I wrong?
<Nope. As mentioned above, general hardness (measured with the dH scale) is simply a measurement of a different group of minerals than the ones measured by carbonate hardness.>
Anyhoo, got me a GH & KH test kit from API today and started testing out my waters. If you remember, I had performed a complete substrate swap from crushed coral to natural gravel/pebble from Kordon. Please also note my tank consist of a few pieces of driftwood. I tested my tank water and these were my results. PH: 7.4. Ammonia: 0. Nitrite: 0. Nitrate: around 35ppm. Degrees dKH: 4. Degrees dGH: 14 (off the conversion chart that the kit included, 12 was max).
<In this case 4 degrees KH is relatively low carbonate hardness, while 14 degrees dH is a moderately high level of general hardness. A not uncommon situation. This simply means the water here has a fair amount of mineral content, but the carbonate/bicarbonate content if fairly low.>
I then tested my tap water (what I'm using to perform the water changes with).
dKH: 8 and dGH: 10.
<Very different. Here we have quite a high level of carbonate hardness and only a moderate level of general hardness. Quite possibly the water is coming from a limestone or chalk aquifer where almost all of the mineral content coming into the water is carbonate/bicarbonate salts.>
Now, when mentioning fish's preference of water hardness and stating a value, we are going with my dGH reading. Is that correct?
<Most books tend to quote the general hardness (degrees dH) range, but do also note that high levels of carbonate hardness become more critical for hard water fish like Tanganyikans, livebearers, etc.>
If so, should I be mixing my tap water with purified drinking to be able to bring down the dGH value since it is so high?
<No. It's not that high. Unless you're keeping Cardinal tetras or Apistogramma, your tap water is well within the margins for most standard freshwater fish. The high level of carbonate hardness is actually quite beneficial because it means the pH will be very stable. As a rule, the bigger the fish, the less fussed it is about water chemistry. Since you seem to have a taste for large fish, don't worry about it too much. Acclimate new livestock to your aquarium conditions and then simply use large (50%) water changes on a weekly basis to keep the aquarium water chemistry the same as the tap water chemistry.>
Is my tank water's dGH value higher than my tap water due to the crushed coral that I had previously?
<If there is still some limestone or coral in the tank, then yes, more than possible. A small amount won't make much difference either way, but if there's a lot still lying about, you may want to remove it.>
Is my dKH value from the tank water lower than my tap due to the driftwood?
<Possible. Driftwood releases tannins and these are acids that combine with carbonate and bicarbonate ions. It all depends on the quantity of driftwood. In any case, doing big water changes will minimise this effect.>
I always thought that monitoring PH, Ammonia, Nitrite, and Nitrate was enough to be able to keep fresh water fish and I completely got that idea hands down and how the nitrogen cycle works. Now this hardness is getting me confused.
<Don't let it confuse you. A hard water, freshwater aquarium is about the easiest tank there is to maintain. The carbonate hardness will control pH, and all you need to do is replenish this "alkalinity reserve" by doing large, regular water changes. Easy peasy.>
Please help me if you can. My goal was to have one Jardini and one Scarlet Pleco in the 170 gallon tank. Are my conditions way off at this point?
<They're fine.>
If so, what further steps should I take? Please advise. Thank you so very much for your time and patience. Andy.
<I hope this helps. Do read the article on water chemistry, here: http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm . Cheers, Neale.>

pH and KH lowering, FW   11/26/07
hello! I have been struggling with PH and KH problems for 2 years now. I used to keep African cichlids so lowering Ph and KH was never a problem-until I decided to get tropical fish instead.
<Oh?>
In my 29 gallon tank, the PH rests at about 8.5 and the KH at 17. Something that shocked me was that the GH tested at 2. (could high PH and soft water exist?)
<Ah, you're getting your wires crossed here. A general hardness test kit measures calcium oxide. Some test kits translate the results into the equivalent hardness in calcium carbonate for historical reasons (I believe this is primarily in the US, but could be wrong). Regardless, the chemicals involved are measuring calcium oxide. So, a general hardness reading of 2 degrees dH means there is a low concentration of calcium oxide. Nothing more, nothing less. A carbonate hardness test kit measures carbonate and bicarbonate salts, and gives the result in a scale based on concentration of calcium carbonate. So, a carbonate hardness of 17 degrees KH means there is a very high concentration of carbonate and bicarbonate salts. Yes, you can have these two things happening at the same time. Imagine a glass of water into which you'd added some salt and some sugar. One test kit might measure salt, the other sugar. Simply because one was high wouldn't mean the other would have to be low, because they're independent variables. While it is *often* true that water with a high carbonate hardness often has a high general hardness as well, there's no natural law that says it has to be so. It's merely something that tends to happen for various geological reasons.>
I also decided to test my tap water. The PH was a perfect 7, KH at 17 and GH at 2. I suspect my high KH to be altering the PH.
<Carbonate hardness does tend to raise pH, yes. But so too will ammonia, so check that.>
I used to have rocks in my 29, but I took them out about a week ago.
They were boiled prior to, but I highly doubt this has anything to do
with the problem.
<Boiling calcareous rocks (such as tufa rock) will have precisely zero effect on whether or not they raise the carbonate hardness.>
I have searched online a bit, and one recommendation was to mix water with Hydrochloric Acid... sounds incredibly risky and dangerous, but could be worth it.
<No, no, no. There's no point forcing the pH downwards if the carbonate hardness is high. Try to understand this critical fact: pH doesn't matter, hardness does. Fish (mostly) don't feel pH (though they certainly don't like rapid pH changes). What directly affects them is hardness, because this controls [a] osmoregulation and [b] the pH stability. Hard water, whether we're talking about high general or carbonate hardness, is not intrinsically a bad thing, either.>
I understand that once the KH is at a stable level, the PH will lower and not bounce back.
<No, quite the reverse. The lower the carbonate hardness, the less stable pH becomes. That's why marine aquarists worry about carbonate hardness so much. It's the "alkalinity reserve" that fixes pH. All tanks have a net tendency towards acidification; tanks with a high carbonate hardness tend to resist this extremely well between water changes, making the fish happy. Tanks with low carbonate hardness experience rapid pH drops, and this makes fish very unhappy. The art of soft water aquaria is finding ways to stabilise pH without relying on carbonate hardness. This is not easy to do! For all practical purposes, community freshwater tanks should be maintained at around 10 degrees dH and upwards of 5 degrees KH where possible.>
Is there any product/chemical/other method you could recommend?
<None. First get a better understanding of your water chemistry and the environment in your tank. For example, are the rocks calcareous? Is the substrate? Then decide if there's really any point changing the hardness, given hard water tanks are more stable environments. Livebearers (poeciliids and goodeids!), Central American cichlids, Rift Valley cichlids, rainbowfish, Goldfish, Pufferfish, gobies and brackish water fish will all prefer hard water conditions. The majority of barbs and catfish couldn't care less, and do fine in hard water, including things like Corydoras, plecs, and most hardy Asian Puntius spp. Choosing fish from this list gives you masses of scope for fun, colourful, weird, and challenging species. Since you won't be messing with water chemistry, your life is much easier, and you can do big water changes to optimise environmental conditions in the tank. A win/win situation.>
PS: RO/DI water is not really an option...
<Collecting rainwater works well if you want to keep a soft water tank. Cheap and easy, and very 'green'.>
Thanks in advance
-Jon
<Cheers, Neale.>

GH/KH concern with new Betta – 10/28/07
Hello :),
I have a 6 gallon tank in my office with a heater (80 degree water), an internal filter stuffed with filter floss (for low current), a few Java Ferns, an Anubias, and some Vals.
<Nice>
I mixed 3/4 R/O water with 1/4 Spring water, and I have had a PH level of 7.2 for a week now. (Without the mixture of water, the PH of my tap water was pretty high at above 8.
<Wow. Liquid rock>
Even the Spring water with the lowest PH reading I found, 7.0, jumped to over 8 in my filtered tank.)
My GH and KH readings are at about 53.7ppm (if I'm understanding the API test kit.)
Some of the articles on the internet seem to indicate that these GH/KH levels are fine, and others would seem to suggest a raising of the GH.
<Mmmm>
I understand that there are products like Kent R/O right and GH Botanica plus from your website. But I know that Bettas like somewhat soft water, and I'd rather not affect my PH if I don't have to, so I'm wondering if I can leave this alone, or if that would be harmful to my new friend over time?
Thank you,
Patricia
P.S. I will be cycling with Bio-Spira, and Thanks for keeping up such a great website!
<Thank you... and I think you are fine here with the calcium and general hardness... for the plants, Betta... I would not change your stated protocol for mixing water. Cheers, Bob Fenner>

Re: GH/KH concern with new Betta – 10/30/2007
Hello,
Thank you so much for your quick response :). It's a scary moment, when you think after weeks of research, you may have actually made things worse for your fish! Thank you for sharing so much of your time with those of us who need it :)
Thanks again :),
Patricia
<Am very pleased to help you, others to improve their experience, the lives to the life in their care. Cheers, Bob Fenner>