Stealth Cat Shadows Corys – 9/24/07
Hi there Neale,
<Hello Lisa,>
Hope you are well.
<Likewise.>
A couple of weeks ago, I installed lunar lights into one of my communities tanks so I could observe nocturnal behavior. Very interesting!
<Indeed...?>
Last evening one of the two Microglanis iheringi made an appearance. When it does appear, it quickly scales the length of the large piece of driftwood and dashes about the substrate chasing everyone off. He is quite the character. His behavior last night was unusual in that he was literally shadowing one Cory at a time - as if he were trying to latch onto to their bellies in a horizontal position (his dorsal fin to their bellies). The Corys didn't like it naturally - they raced about the tank until the bumblebee gave it up. The bumblebee tried this on 2 or 3 Corys within a 10 minute timeframe.
<Hmm... more likely schooling behaviour. Microglanis iheringi is a social species, and some small catfish will form mixed schools if conspecifics aren't available. I bet if you added two or four more Microglanis iheringi, you'd find them schooling together and ignoring the Corydoras.>
I woke up at 4am and gazed into the tank and the bumblebee cat was exhibiting the same behavior.
<OK.>
Do you suppose this is about aggression? Territoriality? Mating?!
<None of the above. Microglanis iheringi is completely peaceful (except of course to small fish it can eat!).>
And may I please ask you a question pertaining to the Mbunas and stabilizing their pH at 8.0-8.2 and appropriate kH?
<Feel free.>
For the past couple of months, I've incorporated crushed coral and shells into the filtration and tank however the highest I can raise the pH with this method is 7.8. I've been able to elevate the kH only about "5 notches" which isn't close to ideal level. Should I begin to add a chemical buffer to necessitate the ideal levels?
<What's the precise value? One of the misunderstandings in the hobby is the idea Lakes Malawi and Tanganyika are incredibly hard, with massively high levels of carbonate hardness. While they certainly are comparatively hard compared with, say, the Amazon River, the general hardness (dH) values of the two lakes aren't incredibly high, around 6-10 degrees dH for Malawi and 10-12 degrees dH for Tanganyika. My local tap water, drawn from a chalk aquifer, is harder than this, around 18-20 degrees dH! What makes the two lakes special is the composition of the salts in them, in particular their relatively high levels of carbonate hardness. The salts in Tanganyika are about 2/3rds carbonates, and in Malawi about 4/5ths carbonates. This has a particular effect: while the waters in these lakes might not be phenomenally hard, they are extremely stable in terms of changes in water chemistry such as pH. Anything about 8 degrees KH should fulfill this criterion comfortably. Higher levels simply provide more stability, but up to a point Malawian cichlids are fairly adaptable (Tanganyikan cichlids tend to be less so). Because coral sand and crushed shells dissolve slowly, there's an argument for doing small water changes more frequently if you find the pH and hardness fluctuates too much between water changes (i.e., if your local water is quite soft). In this case, doing 25% water changes instead of 50% ones might make sense.>
Thank you and look forward to hearing from you!
<Hope this helps!>
Lisa.
<Neale>

Re: Stealth Cat Shadows Corys – 09/25/07
Thank you for your response Neale and the detailed information.
<Not a problem.>
With the crushed coral, I've essentially taken the Mbunas (Lake Malawi) from extremely soft water to a level to about 107.4 kH or 5 degrees dH which falls below the ideal 8 degrees dH you mentioned.
<Does not compute... does not compute! There's no such thing as 107.4 degrees KH. That would be a solid piece of limestone! The KH scale as far as aquarium water goes runs from 0 at the soft end to over 20 degrees KH, which would be very hard water. Each degree KH is about 17.9 milligrams per litre calcium carbonate, so 107.4 mg/l CaCO3 would be about 6 degrees KH. That is fairly low, and a bit short of what you want for Mbuna.>
The pH holds at 7.8. I change 25% of the water every other week. With this notable incompatibility, shall I hold my current position or in fact introduce a buffer/hardener?
<You have two ways forward, each with its pros and cons. You could improve the chemical filtration in the system. If the KH is staying too low, that means the water isn't passing through enough crushed coral. An undergravel filter is the classic way to fix this: a substrate of coral sand on top of a gravel tidy on top of coral rubble will comfortably buffer the water to a nice high pH. This is the system that has been used in marine and Rift Valley cichlid aquaria for generations. On the plus side, this works well and is cheap and easy to set up. On the down side, it requires a bit of maintenance, particularly if the undergravel filter *is not* part of a reverse flow filtration system. The problem is undergravel filters suck up the dirt, so the substrate needs cleaning periodically (typically a good stir once a month, and a deep clean once every year or two). The second approach is to add Malawi salts. These are, in my opinion, more effective and economical than buffering liquids. Since you're "halfway there" in terms of providing the right water conditions, you probably won't need a full dose of the salts to get a nice high KH. So mix a half dose into the next water change, and see what happens. Obviously avoid doing a rapid change in water chemistry -- changes to the better, if too rapid, can still be damaging to fish. So do a 25% water change with the hardened water, and then another next week, and so on until the water is completely replaced.>
The Microglanis iheringi are rather tough to find...
<Funnily enough, a local pet store in London I visited yesterday, Wholesale Tropicals had some! So anyone in the UK interested in these lovely fish... that's where to go!>
I so much enjoy watching the catfishes' behavior - the Plecos (they finally took to the lettuce!), the Corys and these bumblebees.
<Ah, the joys of catfish. Addictive, aren't they?>
I NEED bigger tanks for more fish! I am experiencing what Joyce Wilkerson calls a "marine décor explosion." !! (Clowns will be next adventure.)
<Tell me about it! Fishkeeping, once you're on a roll, is bad for the bank balance. But it's like having your own personal zoo, with fascinating critters from all four corners of the Earth. It's a great hobby.>
Thank you very much for your help Neale!
Lisa
<Well, hope this helps, Neale>

Water Chemistry, FW... hardness, pH    9/7/07
Hello to whoever answers,
<That would be me.>
I am very new to this and apologies for my unsophisticated questions. I did a test on the current water in my five gallon tank. Everything was great except for the nitrates being a bit high and the tank is due tomorrow for cleaning so that may fix that reading but the alkalinity of the water is out of sight at 300.
<Please understand that isn't "high" in a general sense. It is high relative to what soft water fish like tetras and angelfish enjoy. But it is just perfect for hard water fish such as livebearers and African lake cichlids.>
I have a water softener but do have an outside faucet that has only hardwater. I looked at ph adjusters but the instructions were very vague.
<Don't ever used water from a domestic water softener in a fish tank. It is very screwy in terms of dissolved chemicals. It IS NOT the same thing as soft water. All domestic water softeners do is replace one kind of mineral (the sort that furs up pipes) with another kind (which doesn't). As far as the fish are concerned, it's just really strange water with far too much sodium and not enough calcium salts.] Always use the unsoftened water from the drinking water tap.>
I have Chuck the Betta and four platys. They look fine but as I failed with a betta in another tank, I know that can change quickly.
<Platies will thrive in hard water. If you have "liquid rock" as we call hard water here in England, just stick with fishes that like hard water. Apart from platies, the other livebearers will do well, as will rainbowfish, gobies, glassfish, and various cichlids. Five gallons is, of course, way too small for anything other than a single Betta. It is absolutely not acceptable for platies, which need at least 10 gallons. They are active, social fish than need swimming room. The males are also somewhat aggressive, so having some swimming space helps here, too.>
My questions are how much ph reducer is safe to get the ph down to 120?
<Please don't. Until you completely understand how water chemistry works, don't try and change it. Since pH isn't measured on any scale that includes 120, you clearly don't understand how water chemistry works yet. So leave well enough alone. Buy fish that like hard, alkaline water. Use the unsoftened water. Do frequent water changes. That's plenty enough to master just now.>
Is the hardwater preferable?
<99 times out 100, yes, it's better to buy fish that match your ambient water conditions. They will be healthier and breed more readily. Moreover, you can do big, regular water changes (50% weekly is ideal) without worrying about changes in water chemistry or the expense of softening water.>
Is this a reason for the sudden mess of algae?
<No.>
I also need to warm the water but is there any heater safe for such a small tank?
<You don't have a heater yet? Go, now, buy one.>
I got one with the tank and it is a 25 watt Slim-Tech.
<Sounds fine.>
Thank you very much,
<You're welcome>
Linda
<Neale>

Water Chemistry II... pH   9/7/07
Thanks Neale,
<Hello Linda,>
I got the PH reducer number of 120 off the test strip bottle.....Quick Dip.
<Does not compute... does not compute... The pH scale runs from 0 to 14. There's no 120. I suspect you are reading something else by mistake, perhaps general or carbonate hardness (both of which could be 120 mg/l).>
I have done book and internet research but everyone seems to have answers that vary just enough that I get more confused than informed. I am glad I found WWM. I promise not to become a permanent feature.
<Hah!>
I do have to throw in how disappointing it is how little correct information comes from the places where you get these poor fish.
<Indeed. But you have to remember the motives. Pet stores want you to keep coming back to buy stuff. They want you to have just enough success to stay interested. But they have no vested interest in your fish staying healthy provided you keep buying more fish from them. People like us here at WWM don't get paid for what we're doing, we do it because we want you to enjoy your hobby and your fish to stay healthy. Who you gonna trust?>
I will switch to the untreated source of water and test it to see what it is like too.
<Good.>
Will the platies do ok until next month when I am rich again and can get a larger tank?
<Yes.>
And cycle a new tank. I have the 5 gallon tank on a regular sturdy table. Will a ten gallon tank need more support?
<Quote possibly. Depends on the table of course. If it's strong and well built, could be fine. If it's a rickety thing, then don't bank on it. I have a 10 gallon tank on a cheap chipboard TV stand thing, and that works fine. So there are plenty of budget options out there. Just buy something designed to support serious weight. TVs are heavy, hence the TV stand was a good choice.>
Are four platies too many for ten gallons?
<Four will be fine in there, you could probably keep twice that many without problems, provided you kept on top of water changes and didn't overfeed them.>
Is the 25 watt heater sufficient for ten gallons?
<Depends on your air temperature. If your home is centrally heated and never gets that cold, should be fine. If the tank is in an unheated room, might not be so effective. But my guess is you'll be fine.>
Sorry I wasn't using it but I was afraid of "cooking" the poor things.
<That's what a thermometer is for. Get a cheap sticky LCD one (costs about $1) and stick it on the tank.>
I need to move their tank as it is too close to a door and in the winter may be too drafty.
<Quite possibly.>
When I clean the tank today, I am going to clean the algae off their rocks and plants with a new toothbrush and just plain water. Is that ok?
<Leave the algae: your platies will be eating it, and it's very good for them. They are vegetarians in the wild, and 50% of their diet in aquaria should be algae-based, either algae itself or "livebearer" flake food that is made from algae. The only place algae needs to be removed is the front glass. I leave it everywhere else, because it looks nice and the fish like it. Also, I don't like creating work for myself.>
I have read that turning their light on less will help with regrowth.
<No, doesn't work that way. Instead of green algae, which the platies eat, you end up with low-light diatoms, which platies don't eat. Algae is harmless. Sit back, and learn to ignore it. I'm sure you have lots of other projects you could be doing. Scraping off algae is not one of them.>
I have seen Magnets for sale for algae and have no idea if that is workable. Anything else I can do?
<I use a plastic fuzzy kitchen scourer thing for cleaning algae. Cheap and cheerful.>
When I prepare the new tank, is it better to use bottle bacterial preparations or water from the current tank?
<Take some of the filter media from the old tank (30-50%) and stick into the new tank. Much better than bottles, and a million times better than water.>
How will I know when the bacteria is where it is supposed to be?
<Do what I say above, and it's a sure thing.>
I knew nothing about cycling with the five gallon tank and was lucky all of them survived and want to make a move better for them this time.
<Very good.>
I really enjoy my fish and intend to get better at this. My fish and I thank you for improving their world.
Linda
<Glad to help. Enjoy your hobby. Neale>

Re: Fantails - pH and Hardness – 08/17/07
Hi Neale,
Sorry to be a pest. Just want to check in with you regarding the hardness and pH status of the fantails tank. The crushed coral has brought the pH to nearly 8.0. This exceeds their range of 7.6 (obviously) and the hardness has not increased from very soft. Am I endangering the fantails with this pH level? They are happy however I want to make sure this is the right thing.
Thanks Neale. You are great. :)
Lisa.
<A pH of 8.0 is fine for goldfish. Here in England the pH of our very chalky water can get to 8.2, if not more, and goldfish positively thrive in it. It's important not to fixate on pH; it's the total dissolved solids that actually matter biologically, the pH is simply a useful first-pass approximation. Anyway, the calcium carbonate should be raising the carbonate hardness (that's the KH test kit). The dH test kit is measuring calcium oxide, which crushed coral doesn't contain so much of. The main thing here is that the dissolution of coral into freshwater is slow. If you're doing a 50% weekly water change, there will be only a modest increase in pH and hardness over time. The main reason for adding the crushed coral is to act as a buffer; if the water becomes acidic (which is normal in aquaria) the coral will prevent it. Dissolution is faster in soft/acid water than hard/alkaline water. So it's more an insurance policy than anything else. Bottom line, if the fish are happy, and the pH stays between 7.5 and 8, and the KH is around 5-15, and the dH around 10-20, your goldfish will be thriving. Cheers, Neale>

Re: Increasing Water Hardness, for Mbuna f's   8/13/07
Hi Neale,
<Lisa,>
The pH in the Mbunas tank is beginning to rise with the use of the crushed coral as you prescribed.
<Very good.>
Strangely, the water hardness remains extremely soft with no change. Is this unusual?
<Yes, unusual. Crushed coral consists almost entirely of a mineral called aragonite, a variety of calcium carbonate. Aragonite is "unstable" in geological terms and dissolves readily, in doing so, the concentration of calcium ions and carbonate ions will go up. This is what is making the water's pH rise. You should also see an increase in general hardness (which measures, among other things, calcium ions) and carbonate ions (which measures, alongside bicarbonate, carbonate ions). Anything else doesn't really fit the science (at least as I understand it). Regardless, don't worry about it too much. Crushed coral is self-buffering (if that's such a term) meaning it won't raise the pH beyond about 8.2, however much you add. This is well within the preferred zone for Mbuna, so you're laughing. The main thing is watch the fish, and check their behaviour is normal; if it is, assume the water chemistry is fine. Provided you do regular water changes, and perhaps once a month clean out the crushed coral, maybe changing 50% of it and hot-water cleaning the rest, everything should happen nicely in the background.>
Looking forward to hearing from you! Thank you. Lisa.
<Cheers, Neale.>

High pH but soft water
Hi Crew,
<Ave.
I've been reading through your FAQ pages on water chemistry and have found a lot of info so far - thanks for all your efforts! I had an additional question or three (or four) that I didn't see the answer to.
<OK.>
A little background: we have two 55-gallon freshwater tanks. One holds a single full-size Oscar, and the other is a community tank with cherry barbs, gold barbs, platys, neon tetras, Cory cats, and several healthy live plants and some real wood mixed in with the plastic plants. Oh, the Oscar tank also has a large piece of real wood. Both receive excellent filtration (Fluval canister filters as well as HOB filters), steady heat, regular maintenance, and weekly partial water changes. Ammonia and nitrite = 0, nitrates < 10 ppm.
<All sounds fine.>
So... Our water has a pH in the range of 8.4 - 8.8 right out of the tap - I read elsewhere the FAQs that apparently the water in Massachusetts is purposely adjusted this way to protect the pipes. However, the water also happens to be very soft - only about 1 dGH and 2-3 dKH. This high pH, soft water is a less-than-usual combo as I understand it, but not impossible to get. Perhaps the city is also adding a softener to the water.
<High pH and low hardness can come about in multiple ways. Sometimes its an artifact of the test kit being used: if your water has a high permanent hardness (chlorides etc.) but a low temporary hardness (carbonates etc.) a General Hardness (dH) test kit will register "high" hardness but a Carbonate Hardness (KH) kit will register a "low" hardness. Soft water with high levels of ammonia can also register a high pH, because ammonia raises pH even though it doesn't make water hard. Domestic water softeners also mess around with water chemistry in ways producing something not really suitable for fishkeeping. In any event, the water you have isn't acceptable. At the very least, I'd be added a carbonate substrate to the aquarium and/or adding "Malawi" salts to the water to raise the KH so that the water will be much better buffered than it is now. I'd then be selecting hard water fishes such as livebearers or Tanganyikans or rainbowfish that will thrive in the resulting water conditions. By doing this, the mechanics becomes a no-brainer and I can forget about water chemistry.>
Anyway, Question #1: My first main question is about the softness of the water. I understand about low KH and the risks of rapidly dropping pH if there is no buffering capacity in the water. But is there anything INHERENTLY harmful to fish about very soft water with low GH? If soft water is bad for other reasons, what are those reasons? And is it worse to have low GH or low KH?
<Not if the fish have adapted to it. Don't expect the fish to breed readily, but who knows?>
I'm asking because in both our tanks, the water ends up being about 7.4 - 7.7, and I have tested the pH regularly and have never observed a crash or even a significant change in it from week to week, even with all the wood in the tanks.
<Indeed, the wood is acidifying the water, and if you're going from pH 8-point something to 7.4 between water changes, that's really not good. Raising the ambient KH should prevent this.>
So either my test strips showing low hardness/alkalinity are wrong (although they're new), or the system is simply stable enough week-to-week by itself to hold its pH steady.
<Large water changes "temporally buffer" chemistry changes by diluting them. Whether you consider this stable or not depends on your point of view.>
However, we have had some untimely demises in our community tank, and I'm wondering if it's because the low GH of the water.
<Probably a factor, yes.>
I really can't think of anything else, since as I mentioned before, all the other water chemistry parameters are pretty good except for this low GH/KH thing. If the softness of the water is not inherently harmful, then I'd rather not mess with it by adding buffers, for fear of raising the already-kind-of-high pH, you know?
<Raising pH/KH hardness is usually easy. Add coral sand to the tank, and then a reduced dose of Lake Malawi salts to each water change. Experiment to see how much of these salts you need each time. But since high KH water is inherently chemically stable, once you've cross this bridge, it's pretty much idiot-proof. Going brackish water, i.e., adding marine salt mix, does the same thing, and in this case you could keep salt-tolerant things like mollies, guppies, gobies, etc. as well as standard brackish water fare.>
However, if soft water damages the fish in some way, then I'll gladly add something to
change it. What do you think? (The one thing I have read about soft water is that some fish are more likely to breed at certain hardness levels, but we're not breeding fish right now so that's not really a concern.)
<Soft water only "harms" fishes that need high levels of hardness (livebearers, goldfish, etc.) But soft water is also like balancing spinning plates on a pole, you have to keep testing and adjusting stuff all the time. Fish hate rapid changes in pH and hardness far more that they dislike being stuck at something suboptimal on a permanent basis. For example, you can have a tank of cardinal tetras in hard (20dH) alkaline (pH 8) water for years and they'll be fine. But suddenly reduce the hardness to the optimal values for breeding (~2-3dH, pH 6) and they'll die even though those conditions are "better". In fishkeeping, focusing on stability is always better than focusing on the numbers.>
Question #2: Regarding the pH range that I mentioned, most of the advice from the WWM crew that I've read on other pages here seems to strongly lean toward leaving it alone rather than trying to add pH adjusters to bring it down. It seems like it's on the high side, but not too terrible, and fish should be able to adjust to it. Is this also your recommendation for me?
<Up to a point, yes. Because you have a very low KH, I just don't think your tank will be stable in the long term. I've seen pH crashes in tanks too often to be comfortable recommending this as a way forward. It's do-able, but it isn't easy or reliable.>
Question #3: More broadly, I have a question about using something like pH Down in the first place. It seems to me that the whole point of having an alkaline buffer in your water is to prevent shifts in pH, right?
<Well, "point" is perhaps not the right word. Water with high carbonate hardness has a high (= basic rather than acidic) pH, i.e., something over 7. The problem is in common speech we treat "alkalinity" and "high pH" as synonyms, which they're not.>
So oftentimes you hear about somebody adding pH Down (which I think is basically just acid) to their tank and it doesn't do anything, because the acid is just being buffered.
<Correct. It's almost always a waste of time and money unless you've softened the water. Acid buffers are useful when you have a soft water aquarium (say, around 5 dH) and the acid buffer stops the water pH dropping below, say, pH 6.>
So, if someone adds enough pH Down to finally "overcome" the buffer and actually change the pH, won't they be exposing the tank to further, more rapid shifts in pH, because now the buffer's been all used up?
<Yes. This is buffering capacity. Roughly speaking, water at 6 KH has twice the ability to neutralise acid as water at 3 KH.>
Wouldn't this kind of defeat the whole purpose of having a buffer to begin with?
<Buffers work both ways. You can have buffers that fix the pH at acidic values or neutral values as well as basic values. So it depends on what you're after. If you're keeping Malawi cichlids, a buffer that "fixes" the tank at pH 8 is ideal, but if you're breeding Apistogramma, you want something that fixes the tank at pH 6. It's horses for courses.>
Not to mention the fact that by adding all these chemicals, the osmotic pressure in the tank has now been raised way up and stress has been put on the fish that wouldn't normally have been there? So correct me if any of this is wrong, but if that's the case then it seems like using something like pH Down should be done only in an emergency. Thoughts?
<Water chemistry changes SHOULD NEVER be done in response to an emergency. Water chemistry changes are something you do slowly and deliberately to create conditions for certain things, like breeding fish. Otherwise water chemistry STABILITY is what matters.>
Okay, one more. Question #4: Now, if you do think that some kind of buffer is warranted for my tanks to raise the hardness of the water (my first thought would be crushed coral in the canister filter), it seems all but certain that it will also raise the pH, correct? I'm afraid that since the pH already high, adding something this could do more harm than good. It would require using pH Down or something - and see my above questions about concerns over that.
<Coral sand is a buffering agent, because it adds calcium carbonate (among other things) to the water. You can add 5 tonnes of the stuff to the aquarium and the pH will only rise to around 8 and then stop. Buffers *resist changes in both directions*, they don't force changes constantly upwards (or downwards). This is why the pH in a Lake Malawi aquarium is steady: the KH in the water is actually fixing it and stopping it from either going up or down. In your case, creating a tank with a high KH and a pH around 8 would be great, because you'd have a beautifully stable aquarium in which you could keep all sorts of hard water fishes. Have a read of this: http://www.wetwebmedia.com/FWSubWebIndex/fwhardness.htm and then this: http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm .>
This is a lot to be asking at once, I know, but I've seen that you folks prefer it when people ask all the related questions they have in a single email. So, there it is. Any info you have would be greatly appreciated. Thanks so much and talk to you soon.
- Chris
<Hope this helps. Good luck! Neale>

High pH and Hard Water – 07/18/07
Dear WWM crew,
The information I have been reading from the site is really very helpful.
<Cool.>
I have 38 gallon freshwater tank, only 3.5 months old, with10 mollies (about 1" long) and 150 fries, 12 plants and 2 driftwoods in it. Recently I tested my water and found the PH is far too high, about 8.7
<That's quite high, but should be within the range for Mollies. Since yours are breeding like rabbits, you obviously must be doing something right.>
I read lots of information and realized top-off water may have caused the PH to increase as our water is very hard. (Our tap water: close to PH 8.0 / alkalinity 300 ppm)
<pH 8.0 and alkalinity 300 ppm is close to paradise for Mollies. Add some marine salt mix (around 6 grammes per litre) and your Mollies will wet their underpants with joy.>
Test results:
Nitrate: 40 ppm (Kind of high)
Nitrite: 0 ppm
Ammonia: 0 ppm
Total hardness: 250 ppm
Total alkalinity: above 300 ppm
PH: 8.7
(I added Seachem Life Bearer Salt to the tank water.)
<Life Bearer Salt is expensive for what it is. Just use plain vanilla marine salt mix, which you can buy in nice big boxes and tubs to get the most economy.>
I would like to lower PH to 7.6~8.0 safely and try to avoid using chemicals if possible. I am setting up an RO/DI unit. However, I do not know what the correct way is to use RO water to correct the situation here. Hope your great knowledge and opinions can help me.
<Adding RO water will reduce the pH and hardness. But just so we're clear here, RO water isn't the same as softened water from a domestic water softener (a lot of folks get the two confused). You'll need to do some trial and error to see what works, but as a first-pass, mix 25% RO to 75% tap water and see what you get. All this said, unless your Mollies are clearly unhappy, I wouldn't be overly concerned about it. I'm a bit confused about why your aquarium has such a high pH though. If you're doing 50% water changes each week, and your tap water has pH 8.0 when fresh, then I'd expect the pH in the tank to be around 8.0. Driftwood sometimes lowers the water pH. I can't for the life of me understand why the pH would go up so high. Let's cross off one possibility though -- you *are* using a dechlorinator that removes chloramine as well? If you're in an area where chloramine is used to treat water, failure to do so leads to ammonia in the water, and this raises the pH.>
I know this correction should be carried out gradually. A few questions I couldn't find answers on this site, as most information on RO unit seems to be about Marine tank.
<pH and hardness changes should be done gradually, yes, but Mollies are true euryhaline fish meaning they adapt almost instantly. So do a 25% water change one day and then another 25% water change the next and you'll be fine. I've adapted Mollies between seawater and freshwater *within an hour*.>
* Do I need to add anything to RO water before pouring in the tank?
(For top-offs, it is okay to use directly in the tank. Am I right? What about water changes?)
<RO should be safe. Tap water should be treated.>
* Water change using RO water - What's the safest amount I should try each time?
<Never ever add RO water straight to the aquarium *except* when making good small losses from evaporation. Mix the RO water with the tap water, and add *that* to the tank. I personally like to do 10-15% water changes every day or two on some tanks, but other times as much as 50% a week. There's really no maximum amount provided the water going into the tank has roughly the same pH and hardness of the water taken out.>
* What's the ideal alkalinity I should try to achieve?
<For Mollies, the harder the better. They don't care.>
Anything else I should be aware about using RO/DI water to reduce the alkalinity and PH?
<Not that I can think of. Just mix it with tap water first, and test the result to see it's something good for mollies. Around pH 8, 20 dH, SG 1.003-1.005 is just about perfect for them.>
Thanks a lot for your help in advance!
Kathy
<Good luck, Neale>

Re:  High PH and Hard Water – 07/18/07
Dear Neale,
<Hello Kathy,>
Thanks so much for your very detailed reply. I understand why you are confused about my tank water PH going up so high if my tap water PH is only 8.0. In May I went back to Taiwan visiting my family and found an aquarium product, which is an ecosystem machine. The company claims that this machine along with the filter I am using will create a natural environment in the tank. So, there shouldn't be any water changes needed except for top-offs.
<Ah, well, it sounds as if this machine isn't real helpful. I'm *very* dubious about these machines that promise to remove the need for water changes. If you want to carry on using, then go ahead, but I'd still be doing 50% water changes each week simply to keep the pH and hardness at healthy levels. If the machine is removing some nitrate in the background, so much the better, but I personally wouldn't consider any machine an alternative to water changes.>
I set up this machine on June 1 and haven't really made any "reasonable" water changes. I started my first tank in February and now I have 3 tanks...
(still thinking about getting one more, just can't stop... love to watch fish swimming) I read lots of books, magazines and information on website to help me, as I am very new in this. I know regular water change is important, so while I am testing this machine I bought in Taiwan, I am still concerned about not making any water change at all. Therefore, instead of vacuuming gravel and making water changes, I used power vacuum to clean the gravel only, which took out the debris from the tank without taking any water out.
<The debris at the bottom of the tank is harmless. It looks messy, which is why we remove it, but it's the "end" of the food chain, and doesn't affect water quality either way. It's the *invisible* dirt that causes problems, the nitrate, nitrite, ammonia, phosphate, etc. in the water. These are things water changes remove. I just don't trust a machine to do this. So please, go back to doing water changes. It will make life easier for everyone.>
Since the machine was set up, everything has seemed to work fine until I found the PH has been continuously going up. I started to search some answers and information from books or website. What I was told is "Top-off water" would continuously add more and more minerals to my tank and cause PH to increase if my tap water is very hard. That is why I started to think "our hard water" is the cause and wanted to use a safe way to correct the problem.
<I think your analysis is sound. In "the wild" calcium carbonate is removed from the water in a variety of ways, for example by plankton turning it into what (eventually) becomes limestone. Some gets converted in CO2 gas as well. But in the closed system of an aquarium these "sinks" as they're called don't exist. The calcium carbonate will keep accumulating. Water changes keep the calcium carbonate level fixed, because the water going out is matches by the water going in. But if you're adding calcium carbonate in the top-up water while never removing any through water changes, then that calcium carbonate will just accumulate. Whatever the mechanism, I don't like this at all. Do the water changes!>
I still make water changes for the other 2 tanks, so the PH isn't that high like the 38 gallon one which has the special eco machine set-up. What I want to do is try to bring the PH back down to 8.0 by making some gradual small water changes using mixed RO and tap water. Once PH is 8.0 and stable, perhaps top-off water can be 100% RO water?
<See, you have experimental data! I think the "eco machine" sounds a fun toy to play with, but I'd be doing water changes as well to find a "happy medium" where I get good water quality *and* the right pH/hardness levels. I just don't believe -- at all -- any aquarium can be safe without *any* water changes. If such things worked, we'd all be using them. I'm not saying it's a con or dangerous, but I think you should use some common sense. It clearly is causing a problem here, and the fix is nothing more difficult than a water change. So do water changes... see what happens, and change your maintenance regime accordingly.>
The aquarium store in Taiwan I visited has several big tanks with eco machine in them. Water is very clear and tanks have been more than 4 years old. They did not make any water changes at all. That's what made me so interested in giving it a try... as if no water change is needed and fish can really live in a very natural environment; it's certainly a very relaxing/enjoyable thing to keep as many tanks as I like.
<Fish will adapt to all kinds of environments, given time. I read a story in an old TFH book about some marine fishes (Sweetlips, I think) that had been placed in an outdoor pond filled with salt water. This pond was somewhat neglected, and eventually rain had made the water so dilute in the pond that things like water lilies were growing. And how were the marine fish? Apparently just fine! They'd grown to a large size and were thriving and happy pets. Does this mean people should keep marine fish in freshwater ponds? Of course not, but it's an example of how fish can adapt given time. Your mollies have clearly adapted well to the 'eco machine' tank you're running, and since they're breeding happily, no harm seems to have been done. But if this was me, I'd be doing the water changes.>
Hope I cleared your questions in your mind... and the path I am going is right for my fish's well-being. Mollies are very "inexpensive", but I love them and want to make them happiest mollies if I can. I started with 3 mollies... now I have more than 160 in total. (Never managed to count them one by one though...)
<Mollies are excellent fish, among my favourites, and I'm glad you're enjoying them. They've been massively mistreated by the hobby in some ways, and too often I hear stories about sick mollies or aggressive mollies or mollies in too-small tanks.>
Thanks for your help and time in sharing your experience with me.
Kathy
<Well, good luck with it all. I heartily recommend doing a bit of experimentation with water changes to see if that helps. Cheers, Neale>

Hard Water Options - 01/27/2007
I have very hard water, 350ppm.
<Pretty hard indeed.>
I have tried to lower it with aquarium salts but it's not coming down.
<Total hardness is a measure of all of the dissolved solids in the water - thus *adding* more dissolved solids (salt, in this case) will not bring that count down - rather, it will raise it.  Also, some fish aren't too pleased about a great deal of salt.  In fact, some are downright intolerant of it.  A bit, say, one to two tablespoons per ten gallons, is perfectly fine, though.>
So my next question is what are the best tropical fish for hard water.
<Lots of options available to you....  I'd recommend avoiding most tetras and other sensitive, soft water fishes.  There are a few fishes that are very commonly bred in captivity, like angelfish and Gourami, which would be okay with the hardness, though they'd prefer softer water.  Most livebearers (platies, swordtails, mollies, guppies) would love the hardness.  Or, if the tank is large, east African cichlids from lakes Malawi, Tanganyika, or Victoria would be well worth looking into; some of them are very, very beautiful, and they actually *need* hard water with a high pH.  There really are tons of options for you!  Wishing you well,  -Sabrina>

Hard Water With High Phosphates Won't Soften  9/6/06
I've spent a good deal of my morning reading through www FAQ pages as well as any other source I can find online to help with my high phosphates.  Here's the deal, I have two 55 gallon tanks, one is a planted discus tank, the other, a nice little reef tank.  I've managed to keep the water quality on my reef tank at optimal levels by introducing Chaeto to my refug.
Works like a charm.  The freshwater tank is another story all together.  I have about half the 55 gallon planted, DIY CO2, 4 various sized discus, 10 cardinal tetras, 5 Glo-lights, 5 black neons, and 3 Cory cats.
I am currently using PhosGuard (SeaChem) and it works very well, but the problem is my source water, everything out of my tap runs phosphate, ammonia, and pH off the charts (literally), because of the poor water I bought an RO/DI unit, the phosphates and ammonia still come out off the charts. I've thought about purchasing a better membrane but seeing how I have to replace current filter cartridges every 2 months to keep them working, I'm looking for alternatives.  I could always purchase water from a LFS but I'd rather have access to my own source in those times where we need alot of water quickly. I'm open for any ideas you guys might have for me this time. Thanks!
<You need to do some detective work here. Run your water quality tests on the following:
1)Distilled water. You know that this water is distilled from the store and has no minerals in it. The phosphates and ammonia should be zero. The pH should be close to 7.0 but can vary depending on what it can pick up in the air. If your tests show anything then you know the test kits are bad and need to get a new kit with fresh reagents. Powdered reagents work best for me.
2)Now that you know how the test kits are performing then you need to check your tap water. Many areas of the country have high phosphates in their tap water. This is a naturally occurring mineral that come from sand in the aquifers from which well water is pumped out. High nitrates can come from some minerals, but much of it comes from the agricultural practices of using high nitrogen fertilizers.  If your tap water still reads high then we now know that the numbers are accurate.
3)Check the R/O water. The readings should be very close to the distilled water (O ppm). If they are not then replace the R/O cartridge. Measure the R/O water weekly. It should start  out at zero ppm for both. See how many gallons needs to flow through before the readings start to climb. As they start to climb you may need to back flush your R/O unit more often. If you don't have a back flush valve then the membranes won't last too long. You could try getting a bigger R/O unit. If you have a  5 gallon per day unit then a 50 gallon per day unit would take longer to clog just by simple increased surface area. Check out the different R/O units for sale online.
4) Check the tank. These are the most important readings. If the water going in, is pure and the nitrates and phosphates are going up, then the source of the phosphates and nitrates are from the tank itself. The nitrates are from the fish and the phosphates could be from the rocks or sand. Put the rock or sand in a container with distilled water. Check the water in the container in a couple of weeks and compare the test readings. If phosphates show up in the water then you know they are from the rock or sand. Remove the problem materials and replace with inert materials like Fluorite. Do more water changes to dilute the nitrates.-Chuck>