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FAQs on pH, Alkalinity/Acidity for Planted Tanks

Related Articles: pH, Alkalinity/Acidity for Freshwater Planted Aquariums,

Related FAQs: 

You can DIY, or there are general and specialized supplements for planted aquariums.

setting up Walstad aquarium (with pot soil) - plants and PH trouble!     6/6/13
Greetings from Minnesota and of course - thank you for making our hobby better, one advice at a time!
<Salutations from California on this fine day; and thank you for your kind words>
I'm currently setting up my 3rd Walstad tank. I've kept fish for few years now and found Walstad tanks,  with subtropical species quite interesting.
Weather loaches are awesome! (though bad at predictions of weather - they are great at anticipating dinner!)
New tank:
The substrate is made of organic potting mix
(no fertilizers, at least as written on a bag) - about 2 inch thick, .5 inch of fine gravel op top of soil and 1-1.5 inch of smooth white sand (not aragonite)
<Likely silica (Si02) based>
 on top.
Tank is 55g, filtered by Eheim Ecco 2236 (approved for up to 80 g)
PH is a mess, GH is a mess - going from 8.0 in the evening to 5.6 in the following morning. I'm on the first week of this and expect PH to settle eventually.
<Yes; likely "the organics" in your soil are decomposing...
no light phase of photosynthesis to counter as during the day>
2-3 times a week 50% water changes for the first month (scheduled).
Tank is in front of the south-facing window and has a light as well for evenings
The biggest problem for me is the drastic difference between D. Walstad's explanation in the book "Ecology of Planted Aquarium" and my real-life experience. According to author, she is able to set up the aquarium and add plants and fish the same day - and it works!
<Mmm, I wouldn't do this. Diane may well have found a good mix (literally) of soil, sands... but this would be rare for most all>
 No plant die-out, no PH madness, no  crazy algae blooms. But in my experience every single of 3 Walstad tanks I set up goes like this:
Week 1 through 3 - PH is all over the place, any plant I place in the tank dies. Leaves fall off or disintegrate into brown slime. Promise I'm not using agent orange-grade chems in my tanks! :)
<Yes; predictable>
Week 4 through 12 - PH is more stable, plants still die back, but most hardy species (hornwort, Val.s, Cabomba, Anubias) eventually come back. I usually add fish on week 3 or 4. Fish may be stressed out. I also gotten a crazy amount of algae during this time.
 <Also to be expected>
Months 6 and onward - tank is rock solid. Fish are happy. Plants are growing fast and thick! Growth is sustainable for years after. Even moss balls grow faster!
Can you help with this conundrum? Why is my tanks take so long to boot up?, - far longer than "non-Walstad" aquariums, and drastically longer than same-day-add-fish that Walstad describes.
<Likely you and DW's soil sources/types are the majority of difference here... Her's has far less soluble, digestible organic component>
Or would it actually go faster if I break all rules of cycling and add all of the plants and all of the fish now?
<Again; not a good idea>
Would it help to use water from established tanks to top of the new aquarium during the water changes?
<Mmmm, a guess; but this would likely help to shorten the run-in period you describe for your first three systems... But not by much... a day or two>
Or place a plate with crushed coral in the corner of the tank? ( i cannot add it to sand, as the tank will contain Weather Loaches, rehomed from 30 gallon first Walstad tank.)
 <I'd leave off w/ this addition>
Incense, crystals, singing bowls, mood lighting, prayers, motivational poster? I'm willing to try anything! :)
 <Heeeeeee! Ten jumping jacks and barking at the moon at midnight! You might want to read a long while on the Krib... consider experimenting w/ Fe +2 and 3... But really, am a heavy better on the soil... try a different mix... w/ less humic material. Maybe posit your query to Karen Randall, Diana herself...>
Elena E, failed scholar of slow-as-Ramshorn-snail eco-experiment.
<Not a failure yet! Bob Fenner>

Co2 and Ph for planted tank  12/28/10
Dear wonderful Crew
<Hey Patrick!>
Santa gave me a lovely testing kit! I have three running freshwater tanks (29 gallons, 24 gallons and 9 gallons) - all planted with some neon tetra, honey Gourami, panda platy, guppy, cherry shrimps and a few snails.
Ammonia and Nitrite levels all zero.
I've suffered from a kind of brown/black algae on the leaves that is very hard to get rid of.
<There are some VERY pesky, persistent species... mostly blue-greens... that often look black. See "beard algae" on the Net>
I am thinking that it is brown algae. I have been using a liquid carbon mixture for a week now as recommended by a shop that I visited although I am making some DIY Co2 units currently.
My first question is this - from the following results of the tanks, should I be doing anything to my tanks than the weekly 10-15% water change, and weekly / daily fertiliser top ups (from JBL):
<Perhaps a bit larger percentage change outs, same interval... Maybe 25-30%>
Phosphate Po4: (between 1 and 3 ppm - tap=2.5ppm)
<Yikes! This IS high>
Nitrate No3: (between 0 and 10ppm - tap=10ppm)
GH: 300ppm / 16.75 degrees
KH: 160ppm / 8.9 degrees
Iron (Fe): 0ppm (both chelated and non-chelated)
<Need some... I'd up the dosage of what you have commercially, or look into making your own. Easy to do>
Ph: (between 8.4 and 8.7, tap=7.7)
<Why is the pH higher than the tap? Some calcareous influence... substrate, rock, decor?>
My first thoughts were that the phosphate is too high, the nitrate too low! the iron too low! and the Ph too high.
<Agreed on all but the Nitrate... if not zero, you're fine>
I'm guessing that a) the Ph is too high for the tetras and with the high GH/KH/Ph, I have very little Co2 in my tanks. Do you think that my next step would be to mix in RO or rainwater 50/50 as I have seen suggested elsewhere?
<Is a very worthwhile possibility, IF you can be assured that such water is clear of impurities... from roof top, air pollution... Else, you'd do well to consider an RO device. First though, we should discern the source of carbonate, bicarbonate IN your system. The pH cannot rise of its own accord. Something in the tank/s is raising it>
Although my tanks are maintained regularly, could the high phosphate level be caused from the difficulty I am having cleaning the bottom of the tank - it is planted on a substrate with sand. Any suggestions on how to clean such a tank?
<Please read here:
Or is this just a problem with the tap water (Po4=2.5ppm)?
<Of a certainty, at least the start is too high. You may well be adding to this via foods, fertilizers... but you should address (filter out) the initial HPO4 to a large degree... 0.1-0.2 ppm maximum>
And finally, you can see my Iron levels are zero! This surprised me as I regularly put in JBL Ferropol and a daily fertiliser.
Should I up this?
<Yes... your water conditions... likely whatever is elevating pH, and likely your plants' metabolism, is taking up all available iron>
Or is there some other reason why the levels measure zero?
<Aspects of water quality...>
Could this also explain the black on the plants?
<To some degree yes>
Would adding Co2 also help here?
<Yes it would... lowering the pH will help all the way around... one aspect of soluble carbon dioxide in solution>
I have made some DIY units that pump out 2-3 bubbles per second but need to find a way to diffuse this into the water.
<Mmm, do save up for a commercial system. FAR more dependable, adjustable>
Any advice would be much appreciated!
<Cheers, Bob Fenner>

Re: lowering ph in planted tank 7/17/2008 Any recommendations of buffers...SeaChem alright? seems from what I can glean, I'll have to use both acid and alkaline buffer to get the water stable. as well, any resource for finding out what trace minerals, etc., if any, will be needed to get the water ready? freshwater, planted, assorted species (rasboras, Dennison's barbs, Glo lite tetras, Plecos, Corys). thanks <Assuming you have softened the water already, then any commercially available freshwater buffer should work fine. Get one that steadies the pH at 7.0; this is ideal for the widest range of fish and plants. Do also remember that when pH drops below 7, biological filtration becomes steadily less effective. You only need one buffer; if used correctly it will prevent both pH rises and pH drops. There's absolutely no point to softening the water below 10 degrees dH unless you have a specific fish that needs those conditions and will tolerate no other. Ditto carbonate hardness, which should be at least 3 degrees KH for pH stability. Hence a 50/50 mix of hard tap water and RO/rainwater can work extremely well, while also being very cost effective. Remember, soft water is all very well, but if it is expensive/time consuming to produce, that may mean you do fewer/smaller water changes, which is bad! So balance the critical thing (water quality) against the nice thing (water chemistry) and find a balance that works for your time/budget situation. Assuming a moderate amount of hardness, there should be sufficient trace elements and minerals in the water for the fish, and weekly use of plant fertilisers will help on the plant front. Cheers, Neale.>

Re: lowering ph in planted tank 7/17/2008 Darn Neale, you are smart! <Or at least a good bluffer...> Alright, I hope this isn't a stupid question: <The stupid question is the one that isn't asked...> is carbonate hardness the same as alkalinity? <Different ways about talking about the same thing. Where general hardness is merely how much calcium and magnesium salts dissolved in the water, carbonate hardness (and alkalinity) measures the carbonate/bicarbonate salts that inhibit pH changes (or in other words, create alkalinity). Hence carbonate hardness and alkalinity are related, while general hardness is something entirely different. In fact general hardness is perhaps best related to Total Dissolved Solids (or TDS).> if so, the conversation is around 17.8 I believe, so alkalinity should be at least 55 ppm or so (if I did the math right). <Correct, 55 mg/l CaCO3 is (roughly) 3 degrees KH, and what I'd consider the minimum level for an "easy to run" aquarium. Any less, you get rapid acidification and potentially problems with plants (because some remove carbonate and bicarbonate ions during photosynthesis).> my tap water has alkalinity in the 120-130 range (although it does fluctuate from time to time), so if I mix 50/50 with RO or RODI, I will I get roughly 60-65 ppm alkalinity, or is there more to the equation than that. <This is exactly so. If you go visit my web site, I have a computer program called Soft Water Ware that does the specific calculation for working out this kind of thing, called a Pearson's Square. It's free, and it's Mac/Windows. http://homepage.mac.com/nmonks/Programs/softwaterware.html > stated alternatively, what happens when you mix 120 ppm alk, 8.0 ph tap water at a rate of 50/50 with RO or RODI water? <What you'd get is very nice water for tetras, barbs, etc.!> and "dH" you mention - is that general hardness? <dH stands for Deutsche Haerte, or German Hardness. This is the scale used to measure "general" hardness, which comprises both temporary hardness (i.e., carbonate and bicarbonate) plus permanent hardness (things like sulphates). Without getting into too much depth, while related, general hardness and carbonate hardness are important for different things. General hardness (that's measured in degrees dH) is all about osmoregulation, i.e., how easily a fish can maintain its internal water balance. Carbonate hardness (degrees KH) is important to us because it is what prevents pH changes; the more carbonate hardness, the resistant to acidification the water will be. For historical reasons, many general hardness kits, particularly in America, translate their results into the EQUIVALENT amount of calcium carbonate required to get the same amount of hardness by itself. Hence you might get a general hardness test kit with a results card measured in mg/l or ppm calcium carbonate (CaCO3). But it is important to understand that this is a conceit that exists only to make things easier to understand (!!!). The general hardness test kit itself will not be measuring calcium carbonate but calcium and magnesium salts. That's why I prefer to use the "degrees" scale instead of ppm or mg/l when talking about both of these measurements, so people understand that they are entirely different things.> Thank you again. <Hope this helps, Neale.>

Re: lowering ph in planted tank   8/11/08 Neale...brief update. <Hi Paul,> A week ago, did 30g water change with 50/50 RO/tap water. Afterwards, 70-75 alk and 7.4 ph held steady, tested every few nights at same time. <Sounds great.> Did a 55g water change with 50/50 RO/tap water. Afterwards, 70 alk and 7.4 ph. Held steady from water change at noon yesterday to this morning. <Your results sound in keeping with my experience.> Happy with the results. Your advice was spot on. Thanks. <Cool.> One last question - if I see my ph holding in low 7s (which is perfectly fine by me), but my alk continues to drop, what can I do to help get the alk up (knowing that below 50-55 is too unstable)? I know that shifting the 'recipe' to a little more tap water than RO would probably work, but worried it will cause the ph to likely go up. Any other options? <I'd either make my own African Cichlid salt mix (not tonic salt or marine salt!) or buy some off the shelf. Then I'd add to each bucket of water, starting at, say, 10% the dose you'd use for a cichlid tank. See what happens. The next week, add a bigger percentage if required, otherwise the same amount. This would be cheap and easy. African Cichlid salt mix will raise carbonate hardness as well as general hardness, and buffers the pH upwards. Used sparingly it should work nicely.> Thanks again. Cheers! Paul from San Diego. <Cheers, Neale.>

Lowering ph in planted tank -- 07/10/08 Gents and Ladies, You have been a big help in the past, and I am hopefully you can be here as well. I have searched WWM and have found many helpful tidbits of info, but nothing that really hits this on point. Question: How to safely lower ph in tank and continue to do so in fill water - safely! Living in San Diego, the land of liquid rock water, my tap water is 8.0-8.2 ph, with a Alkalinity of 120-130 ppm. I have a very good drop based kit of LaMotte and Taylor products for my pool outside that I use to double check my API drop based kit. All results are corroborated. I have started up a 120g planted FW tank, with 40g sump, that is fully cycled. Inhabitants are 2 gold nugget Plecs, 1 queen arabesque Pleco, 1 king tiger Pleco, 3 Congo tetras, dozen harlequin Rasboras, half dozen Glo-lite tetras, straggler zebra Danio that I rescued from abuse in another's tank, 4 roseline barbs, half dozen cories and two mystery snails. tank is moderately planted. lights are 216w t5, 6500k. substrate is mix of silica sand, eco complete and Schultz's pond soil. I have some gravel over part of the substrate. I hit the substrate and gravel with vinegar before stocking to check for reaction - none. Turnover is about 6-7x hour. No CO2 (and hoping to avoid). <Short answer is don't bother lowering the pH unless you can lower the hardness as well. Lowering the pH on its own doesn't really work because the system becomes unstable and very dependent on adding buffers in the right amounts and the right times. Any variance leaves the pH unstable, severely stressing your fish. There is absolutely no advantage to having a low pH but still hard water, so why bother? I live in a hard water area and simply mix tap water with rain water 50:50 to get something that is roughly neutral in pH and only moderately hard. Most plants and fish thrive in this. There's enough carbonate hardness to keep the pH stable, but not so much that soft water fish and plants can't do well. If you don't want to use rain water, then RO water is a (potentially) safer if more expensive alternative.> I've read about peat (don't really want to...colors the water), vinegar (don't mind if it is safe...but seems to be conflicting info on that) and store bought stuff (but most of that contains phosphates, and don't want to add that to planted tank for fear of algae bloom, and when I've used that stuff on other tanks, it only works temporarily, and then ph slowly creeps back up). <All this is concentrating on the pH, which is of secondary importance in fishkeeping. Many, likely MOST, fishkeepers misunderstand this. Fish don't care about the pH value; what they care about is that it is stable. The part of water chemistry that is central is understanding carbonate hardness versus total dissolved solids (TDS). Carbonate hardness is what stops pH changing. The more the better in that regard, but as carbonate and general hardness go up, so does TDS, and TDS affects how fish osmoregulate. Fish from soft water habitats have to work harder than normal when the TDS is high if they want to keep their internal water balance right. A similar problem occurs for hardwater fish kept in soft water, except more so, hardwater fish seeming across the board less able to adapt to low TDS than soft water fish to high TDS. In any case, since plants don't tend to be bothered either way, provided you give the right about of CO2 for whatever pH, in planted aquaria messing about with pH is even less important. Indeed, if you are keeping plants that perform biogenic decalcification (e.g., Elodea) and remove bicarbonate ions for the water, you absolutely must ensure that the carbonate hardness of the water remains more or less constant. Many of these plants abhor low pH, and changing the pH is one of the best ways to kill off otherwise indestructible species such as Vallisneria.> I am targeting a neutral or slightly sub-neutral ph (6.6-7.0). How can this be done safely in the tank, as well as for fill water? I would like to avoid CO2 and RO/DI due to cost. <There is no effective way to reduce pH and carbonate hardness without diluting the incoming hard tap water with RO or rainwater. Peat filtration can work if the hardness is relatively low, but it is an absolute dog to do cleanly and reliably, even before you think about how you going to stabilise the pH of the water with all those additional humic acids.> Thanks, as always. Paul <Hope this helps, Neale.>

Re: lowering ph in planted tank 7/10/08 Then RO it is...thanks for the help Neale. <Very good. Hope it all works out, and be sure and monitor carbonate hardness (KH) so you don't get crazy pH swings. http://www.wetwebmedia.com/FWSubWebIndex/fwsoftness.htm Cheers, Neale.>

Need Help :(... Planted Tanks, CO2, Water Hardness    7/20/06    This is going to take a while to write down , I live in an area where the tap water is 0 KH and GH with a PH of 7 , <Wow! The "Land of RO?"> I recently got a 350 litre fish tank , I like heavily planted tanks so decided to do a lot of research about CO2 injection (The yeast way) <Yikes... need some added buffering capacity...> having made 2x2 litre reactors and staggering the changing of one every week whether it needs it or not I think I have roughly the same constant flow of Co2 entering the tank , The pH dropped on first injection <Oh yes> so I used Bicarb to increase the PH back to 6.9 , Now the water has a KH reading of about 4 to 5 and a GH reading of 0 , <I'd increase the general hardness here...> The problem is this , The PH just wont stay balanced (Not a good thing) I am getting green water (I think this is mainly due to me fertilizing the plants on the same day as I put them in) , The plants stream with oxygen for about 2 hours a day (This is a good thing), Lighting is the standard 30 WATT and 15 WATT Multilux system that comes with a Trigon 350 (Which is what the tank is) . Now , There's a million and one articles on the net about starting CO2 but how about stopping it , What would I have to do . <Turn the count (of bubbles) down by half every week or so>    I love this hobby and I want what's best for my fish and plants and I also want what is best for me (The joy of staring into an aesthetically pleasing tank for hours a day) . The tank has been running around 6 weeks , I used mulm and aged aquarium water from my other 2 aquariums to jump start it (which worked really well ) None of the fish introduced have shown any signs of suffering or illness , All feed normally and squabble and display as they should . Please send me advise on stopping CO2 (Even if I don't use it right away) . Or some encouragement as to what I am doing is ok . The green water is quite annoying and I want that sorted out , <Can, will be with the use of either a commercial product for increasing alkalinity (more than bicarb)> But the priority is in sorting out this PH imbalance , The waver goes from 6.9 to 7.1 sometimes a little lower sometimes a little higher . Temperature of tank 78-80 (But in this recent heat wave it has risen to 84 a couple of times, Nothing I could do about it all 3 of my tanks did this) . PS I have layered the tank with 3 inch of vermiculite under a sand substrate all plants are doing fine , Haven't added fertilizer since initial set up as I thought the algae was utilizing this and wanted the nutrients to be used up so the plants could start outcompeting the algae and hopefully green water would go , Anyway please send me some advice and post an article to for people who want to stop using CO2. <Don't have time, plans for a/the article right now> On initial set up the bottle ran out of Co2 and the PH climb was unbelievable (So I know I cannot just stop it and that's that) I think this was due to me using bicarb to balance the PH and the bicarb was forcing the water to its own PH equilibrium without the presence of carbonic acid to keep it in check . <This is likely the case, yes> You know the KH and GH and PH now , Is it even worth trying to use with such strange water parameters ? , <Yes, still worthwhile. Just need to buffer the water to near the pH you're looking/shooting for> Bah I witter too much thanks in advance for any help you can give me , Yours Antony Piwczuk one stuck guy :\ <Anton... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwph,alk.htm and the linked files at top... Look into a commercially available product to buffer your water near where you want... 7.0... 7.2... Bob Fenner> Planted tank and CO2 question  11/19/05 Hi All, <Craig> I have a couple of questions regarding CO2 and Aeration in a planted tank. Also about pH and KH. <Okay> First off I know that plants take in CO2 and release oxygen while the lights are on and visa-versa when the lights are off. My filtration right now is an Emperor 280 on a 60 gal tank using 4x65 lighting. I have a 2" red Fluorite base with a top layer of coated beach pebble and several pieces of gold quartzite flagstone that I've tested and came out neutral for pH. <Good> Now I imagine my lighting with the amount of plants I will have and the filter will cause a whole lot of aeration during the day. Will this cause the pH to flux a lot from day to night with the heavy rise and fall of CO2 levels? <Mmm, not much likely... there are chemical buffering mechanisms in the water, the effects of "out-gassing" to the surface...> With the assumption that plants are a very good bio filter themselves could I turn my Emperor 280 off during the day and let the plants clean and aerate then turn it back on at night to help with aeration when the plants start taking in the O2? <Interesting possibility, you might try experimenting with> I'm very skeptical of turning off filtration but I also don't want to see the pH go crazy. <Test it and see... shouldn't vary more than 0.1 or 0.2 pH point diurnally> I also don't want to have to get into the whole CO2 fertilization but I will if it's necessary. What would be a better method of trying to stabilize the pH if I do have a problem? <Likely not an issue... unless you have a "BUNCH" of plants, water with little alkalinity...> Also my tap water has a pH of 8.0 and a KH of 7.5. <Oh. No worries> I've tried using SeaChem's neutral pH buffer and it didn't do much of anything. I'm now trying SeaChem's acidic buffer putting in small amounts at a time and it seems to be bringing the pH down. <Mmm, I'd likely blend in some water (reverse osmosis at home about the cheapest, easiest) and leave it at that... systems are almost always reductive, drifting down in pH with time> With my décor being neutral all I have to do is get the pH down to 7.0 and it should hold correct? <Mmm, not hold...> If I add peat wood I understand it will help bring the pH down but how far down will it go if I leave the peat in the filter cartridge? <Depends... I think you may be over-thinking all here... with the exception of a working knowledge of alkalinity/acidity and their confusingly similar terminology with pH conditions. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwph,alk.htm > Thanks in advance for your help. Craig McDowell <Welcome. Bob Fenner> 

pH and Instability - 10/26/2005 My tank's pH is about as unstable as I am! <Yikes! Stabilize yourself, first, hon!> I have a 150 gallon show tank that I converted to a central/south American planted tank 2 months ago. The source water is unfiltered, treated for chlorine/chloramine, and has: pH: 7.5, GH: 3, KH: 5. The tank has a day time pH of 7.8 and night time pH of 8.3, <Yeee-ikes!> GH: 0.5, KH: 5. How do I stabilize and lower the pH without the normal non-plant-safe buffers? The substrate is layered 2" peat, <Mm, I usually recommend keeping peat in a container in the filter instead of in the substrate.... it can become a bit of trouble.> 1.5" 1/8" quartz gravel, and 2" play sand. I did solubility tests on all substrates and they were all null. Decorations are all granite, slate, and driftwood. Lighting is 250w 10000K Ushio MH and 65w 6500K PC (both stolen from my old reef system). I have a small amount of green algae on the sand that the Plecos and snail won't touch. Livestock: 1 med. Angel, 1 sm. Severum, 1 sm. Clown loach, 6 lg. Giant danios, 2 sm/med. Plecos, and 1 2-inch yellow/orange snail (unidentified thus far)...I don't want to put any more in it until the pH is stabilized but I want to do Kuhli loaches and Discus. Oh, I also haven't put any plants in yet for similar reasons...as well as current budget. Please help! <Uhh, are you adding CO2 to this system, perhaps? Though I suspect the peat may have something to do with this, I am really starting to wonder what else might be going on. pH changes with changing CO2 levels, which is why I ask.... Also, is this tank aerated? 24/7? What sort of filtration? Any other system details you can think of? Also confused, -Sabrina> pH and Instability - Addendum - 10/26/2005 Oh, I forgot to include my temps....night time temp drops to 78 F and day time high (because of the Metal halide) is 80 F. I feed twice daily from various Tetra, Wardley, Omega One, and OSI flake foods and occasional Nori for the Plecos and snail. Thank you. <All sounds good so far. -Sabrina>

pH and Instability - II - 10/27/2005 Thank you for the response! <You bet!> I'm at my wits end! <A tough place to be. Take a deep breath and chill, everything resolves with time, one way or another. Take it all in stride....> I'm not using CO2 and I haven't a clue what's going on. <Nonetheless I still wonder if CO2 might have something to do with this.... Uhh, have you got a CO2 test kit? Or can you find one inexpensive enough to purchase just for "the heck of it"? I'm curious as to the CO2 levels in the morning, midday, and an hour or so after lights-out. I don't want you to go out and drop several bucks to satisfy my curiosity for something that might totally not be the issue, though.> I've done the peat moss thing before without buffers and had no problems, though source water was a little bit harder and only pH 7.3. Do you have any more ideas? <Aside from how the peat may be breaking down, my only other thought is toward that hefty lighting. Would you try decreasing the lighting for a couple of days? Maybe to half of what it is? See how that affects the pH, if at all. Though I still think very strongly that the peat may be a contributor, here.> I do se a fair amount of gas bubbles in the sand and the on the algae on the sand directly below the MH. Any and all help would be appreciated! Branon. <Please do keep me updated if you test CO2 or try augmenting your lighting - I would like to see how this plays out. Also confused, -Sabrina>

pH and Instability - Another Addendum - III - 10/29/2005 I forgot to send in the additional particulars of my tank! <Alrighty> I have a 200gal rated Wet/dry with bioballs and a Surge 3500 as the return pump ( I know it is small, but the 9000 we were using burnt out on us). I use a 650gph pond pump to power a 3-jet Under Gravel Jet (different from UG filter....forces water through without buildup as a sort of closed loop) <Understood> and a Maxi-Jet 900 for additional surface disturbance. I pulled out a .5 gal sample during the day (pH 7.8), checked nighttime pH to be 8.3, and then treated the sample with1.5g of Proper Ph 6.5 to see if it is buffer-able...is that a word?... <If not, it's close enough for me.> and the pH is a constant 6.5, both night and day. Granted, there aren't any real heat, gas, or nutrient exchanges going on, but that was at least somewhat encouraging. I'm also looking at filtering my source water (Sediment, Carbon, Poly-Filter idea previously posted or an RO or DI). What do you think is going on and how do I fix it...short and long-term? <Here I'll ask if any of the system components you've mentioned above were not thoroughly cleaned after using in the saltwater system.... and chance of salt creep, calcium deposits, and so forth in/on any of these? -Sabrina> pH and Instability - IV - 10/29/2005 Sabrina, you're a doll...an absolute doll! <Hey now, I haven't really done anything yet! If we get this figured out, THEN we'll go for those kudos.... ;) > I've been unable to find a CO2 test kit...is there a DIY kind of thing for this? <Mm, I really don't know. Plenty of online etailers sell them, if that helps any. You might try a Google search on CO2 test kits.... maybe including DIY in the search.... I imagine if you could find out the reagents used, it could be done.> I'm gonna try the light thing. Here are my questions re: the whole thing: 1. The lighting should only affect things if there's photosynthesis going on? <Correct - and if there's enough algae growth to affect CO2, that might be affecting pH.... Just an idle thought at this point.> 2. Is that a significant issue when the only photosynthesis going on is via algae? <Possibly. Just trying to explore everything I can think of, here; to be quite honest, I'm really not sure what's causing these fluctuations.> 3. Would using RO stabilize the system? <If you have an RO unit, it's worth a try. Again, though, I don't know that this will "fix" the problem. I'm still not sure what the problem is. And I'm more than hesitant to suggest you go spend the bucks on an RO system when I totally don't know that it will help.> Should I consider CO2 injection? <With the tremendous amount of light you'll be offering to your plants? I would. Or back off on the lighting quite a bit instead.... lots of options, really.> 4. I thought peat and bog wood were supposed to buffer acidity? <They release tannic acids which do drop the pH - I really think there's something else at play, here, and my biggest thought now is toward the equipment and filter media you're re-using from when this was a salt system.> 5. In my original setup I had aragonite sand and I wasn't able to get some of it out, like 40 grains...could this be having some effect? <That's, what, like a quarter of a teaspoon of sand? I don't think that's significant.> If so, when would it wear off? Is there anything to accelerate it? <The more acidic the water is, the faster the aragonite will dissolve.> 6. Would water changes vacuuming the sand surface (thus reducing the algae) be effective? <Water changes might help.> 7. Will the CO2 in the peat reach an equilibrium? If so, when? <Uh, oh man, I wish I were still sitting in Hawai'i next to Bob answering these things.... I'd be looking for a chemistry lesson on this one.... Uh, if I'm getting this somewhat right, organic (carbon-based) things breaking down do produce CO2.... I think.... But.... looking for this to "reach an equilibrium"? Not sure what you are expecting here. And, as you mentioned above, I would not be expecting this to RAISE your pH. Quite the opposite.> 8-20. I just had to make up the difference, since I've already come so close to '20 questions.' :-) <Ah, fair enough. Hope we're getting closer to some ideas for yah - I do very much want to know how this plays out!> Thanks. Branon. <Your partner in confusion, -Sabrina>

pH and Instability - Some Headway! - V - 10/30/2005 Sabrina, I just checked my day and night-time pH after reducing the lighting to a 25W PC (6500K). Daytime pH is @ 7.6 and night-time is 7.6....that's lower than it was before and actually stable! <Alright, some headway indeed! I would be curious to know if it remains stable over the course of a few days, and if you can recreate the problem by turning the bright lighting back on.> I cleaned all the equipment well after the saltwater but didn't after the Mbuna...though that has been 2 months ago now. <Probably not an issue, then - but I wonder if perhaps there were mineral deposits left over on the bioballs.... just a thought.> Ok, so if the pH is steady with the lowered light...what does that mean? Does it mean that the CO2 put off from the algae is so outrageous that it is raising the pH at night that much...? <Mm, actually, as CO2 concentration increases, pH decreases. During the light hours, plant life uses CO2 during photosynthesis and pH can/should rise as a result. In the evening, you'll get your highest pH reading, and an hour or so after lights-out you should start seeing pH drop, and CO2 increase. This is why folks who inject CO2 usually employ a pH controller that will turn on/off the CO2 system at proper times to keep pH stable.> I sent you those pictures of the system and it really doesn't seem that over-run by algae.. at least not to me. <The pics never did come through, so I don't have input on this for you.> Does this rule out the breakdown of the peat as a causative agent? <Again, I would suspect this to *lower* the pH, not raise it.> I don't have any shielding on the MH...yet (haven't put it on yet)...could the unshielded UV be the cause? <In all honesty, I just don't know.> The water has seemed quite green, could it be I'm working against ....that 'd' algae (sorry, I forgot the name)? <'Damn'? 'Detestable'? Oh, you mean 'diatoms'? Uh, at least 'green water' algae, for sure.> Could that be the ultimate culprit? <Could be a contributor.... But again, I'm not certain of this. That you have decreased the lighting and pH has stabilized does make me think that there was some sort of connection there.> I'm just grabbing at straws here. <Me too, hon.> Oh, the pH of the separated, buffered .5 gal sample is still holding at a pH of 6.5. On a side note, do you know anything about FW snails? <A little bit, not a great deal. Mostly just which ones can/will be eaten by Botia striata.> We have had an unidentified 2" yellow/orange snail in our system for almost 3 weeks. <Probably an apple/mystery snail.> Until 3-4 days ago it was very active and ranged all over the aquarium. Our water quality hasn't changed (out-side of the now stable pH) but he suddenly started floating around the aquarium. <I understand they will do this to find preferable water conditions - in the wild, they just start floating about, and when they're happier, stick around again. I suspect the pH fluctuations have caused him problems.> I haven't ever had snails, so left him alone. He 'settled' onto a spot on the substrate and didn't move for 2 days. I was about to take him out as dead, but tonight we found him on the opposite side of the tank, down in some rock, and the wife and I both swear it is moving, though only slightly. I've only target fed it once, a 2" sq. piece of Nori, hoping that it would get enough algae and detritus to help the tank and take care of him...what do you think? <Keep an eye on him for sure. If he's not moving about, pull him out - you'll know the second he comes out of the water if he's dead, and you'll learn an absolutely unmistakable and unforgettable smell. Uhh, and it'd be a good idea to wear a plastic glove or something, lest the smell "stick" to your hand. I learned that one the hard way. I also recommend you check out http://www.applesnail.net .> OH, my Severum and Angel are both taking turns trying to eat a fly from the other side of the glass...! <Mmmmm, tasty!> ...I love cichlids...what other group of FW fish has such character!? <The bony tongues, and the Potamotrygon rays.... ;) > Anyway...Thanks. Branon. <Still have my fingers crossed.... -Sabrina> 

pH and Instability - uh, V? - 11/02/2005 Sabrina, I think I'm more confused than when we started this. <Rockin'! Bring it on.... I'm caffeinated, I can take it!> I turned the 250w MH back on yesterday and have checked the pH. It has stayed at a solid 7.6 without varying. <Uh....> The snail has also come around and is back to his normal self. <Well.... that's good, to be sure.... I bet he's enjoying the stable pH.> So...what was the problem <Hon, I really, really don't know. I am led to believe that there may have been mineral deposits in/on some of the re-used equipment that, as they dissolved, brought up your pH. Perhaps now these mineral stockpiles are exhausted, and you've nothing more to worry about. Or perhaps I'm completely and entirely wrong.> and do I need to worry about it happening again? <I would be cautious for a couple weeks, at least. Give it some time. Monitor it daily, or twice daily - if you see no fluctuation in a couple weeks, I will hazard a good guess that you're safe.> Thanks, Branon. <A delight to correspond with you. Wishing you well, -Sabrina>

pH and Instability - VI, Thanks - 11/03/2005 Thanks, Sabrina, it's been fun. <True enough!> Take care. Branon. <Wishing you well in this and all your endeavors, -Sabrina>

Using peat to lower the pH I have a 25 gal aquarium. I use a canister filter filled only with biomedia (material that provides bacteria with a large colonizing surface) and the regular mechanical filter pads. My local tap water has the following water parameters: pH around 8 (+- 0.2) and KH=7. The fish I want to keep (central and south American cichlids) require neutral water (pH range: 6,8-7.3 appr.). The aquarium is decorated with driftwood, but it doesn't have a measurable effect on the water chemistry (pH and KH are the same with tap water). Zeolite (which I used in the past) did lower the pH and soften the water. With Zeolite I got a pH of 7.3 and KH around 3-4 (Germ. deg.). Zeolite is a cation exchange material which can bind ammonium and other cationic compounds (possibly calcium and magnesium and thus the low KH value). <Yes> However, this not only deprive Nitrosomonas colonies of their food source (disrupting the nitrogen cycle), but it releases species of cations in the water (possibly sodium) which in high concentrations can be fatal for the fish. <This is a little discussed possibility> Now instead of using Zeolite, I am thinking of using peat. Peat binds calcium and magnesium cations and exchanges them for hydrogen cations. So it lowers both water hardness and the pH of the aquarium's water. Moreover blackwater will bring out striking fish coloration! <Yes to all> I have seen many commercial brands that sell aquarium-safe peat. This is probably intended to be used in a canister filter. <Mmm, or a box filter... or in a Dacron bag placed in an area of water flow...> However, I am not sure about what amounts of peat to use in order to bring the water to the desired pH values. I think that using a plastic barrel (with dechlorinated and properly heated water) pre-treating it with a nylon bag filled with peat is safer, as the effects can be controlled before the water change is made. What methods do you have in mind, concerning the use of peat for lowering the pH? <What you describe is fine... the amount cannot be accurately guessed as peats are not consistent in their quality in this application... best to soak, even boil them in a bit of water, let cool, strain (and pour the boiled water in with your mixing water) and use> Does a KH reading of 7 germ. deg. indicate a sufficient buffering capacity or should I experience sudden pH shifts? Thank you in advance. Spyros <Good questions. A dGH of 7 should be fine for buffering. Bob Fenner>

Water hardness Hi Mac L <Hi Lukas!> I'm ok, and your self? <I'm stress cause its Christmas and I am way behind lol> Now I read just about all the links to do with ph and planted aquariums.  But I think I'm a little more confused then before.  K so any thing below GH 200 ppm is soft water, right? Then do I make my water harder? i.e. add fertilizers and such? And what does the KH test for?  Is there a chart on the web, or in a book some where that I would be able to access? <I use this one http://www.practicalfishkeeping.co.uk/pfk/pages/hardness_calculator.php, it also has some frequently asked questions.  Take a look and tell me what you think.> Thanks for all your help. and I don't know if you remember about the red worms.  They have not returned as of yet. <That is wonderful to hear.> Lukas

Water hardness II Hi MacL  <Hi Lukas, how are you?> Lukas here, again.  I am having another issues with water hardness, or so I've been told.  Now My first problems have been worked out there are no worms in the tank, and after doing a 50% water change my pleco has stopped smashing his head in to the cover, the salt like you said.  <Wonderful!>   Now my new issues are my plants.  Any thing new I place in to the tank dies. <Actually the salts would have hurt the plants too so now you should have better luck.> So I wandered over to the LPS, and asked some questions.  I wanted to start up on a co2 system. But was directed in to doing some tests first.  Now Ph is now dropped to about 7.2 and all others were at 0.  <GREAT!>  But the water hardness test I cant figure out, what the results mean.  My GH is 200 ppm, and the KH is 80 ppm.  Is this good or bad and where can I learn more about how to drop or raise if need be? <Just so happens there are some great things on the site. Take a look at this. http://www.wetwebmedia.com/PlantedTksSubWebIndex/acidalkags.htm> I do have 2 types of plants that seem to thrive in the tank.  I have several crypts and 2 Banana plants, and from reading on WWM , they are a little difficult to keep.  However mine are doing great. <You are gonna go far with this Lukas, you obviously care.> Thanks in advance.  Lukas

Water hardness and plants Hello all, I finally got a test for my water's general hardness GH. And, after testing the water in all of my tanks and my various sources for tap water I have a few questions. Mainly, my tap water is too hard- and oddly enough it varies depending on what faucet I use: the kitchen is tap is about 10 dGH where as my bathroom is at 12 (my guess is that the age of the pipes has something to do with the difference). Nonetheless, my concern is with my main tank (29gal) is at 10 dGH (it has a bunch of plants, 6 glass cats, a handful of ghost shrimp and a Betta). I've come to the conclusion that certain species of plants fail to thrive b/c of the level of hardness [all other test are ok: pH 7.2, ammonia -0 nitrite -0]. I'm wondering what I should do to my tap water to make it softer, and what I can add to my tank that may keep the level in check. I've read that certain substrates and rocks, etc. will keep a tank at specific degree of hardness- but I'm looking for something that will keep it at a lower level, say 4-6 dGH. Any suggestions? Thanks a bunch,-Nero v >>Hello Nero; You can try adding peat moss to your filter. Any brand will do, but Eheim makes a good quality peat moss. You will find peat moss at your local fish store. This will lower your hardness and your pH, so add a bit of moss at a time, wait a day or so, then take some test readings to see what the levels have fallen to. You can then add more moss to the filter, if needed, until you reach the level you wish to be at. Also, when you do water changes, you can prepare your water in advance in a large Rubbermaid bin. Run a filter with peat in it so the water will be the same hardness and pH as your tank water. Best Wishes, -Gwen<<

UGF and High pH? - 04/14/2004 Hi guys.... <Hello> I have a 39G high tank that has been set up for 10+ years. All of a sudden my ph is 7.6 , no ammonia, no nitrates, I do a 25% water change 1-2 x a month. <"All of a sudden"....  Have you added any new rock recently?  New substrate?  Anything at all new in the system?> I have a undergravel filter. LFS says that is the problem with the pH. <If the UGF is properly maintained, I doubt that this is likely at all.  Do you regularly vacuum the substrate?  Any large pieces of decor that would create a "dead spot" under the UGF plate?> PH used to be 6 and then it went up and won't go down. My live plants are not enjoying it. Should I just remove UGF.... I know the plants would be happier? <The plants would certainly do better without it, that's for sure.  But I am not convinced that the UGF is the cause of your problems....  Have you tested your source water?  Removed peat or driftwood from the system?  Changed the manner in how you go about regular maintenance?  Added or removed anything at all in the system that may have contributed?> Please advise.  Monica <Hope to help you get to the bottom of this....  Wishing you well,  -Sabrina>

Low pH I appreciate comments on my present situation...  I am in the process of setting up a 54g planted community tank that will have a South American flavor, although it will not be a strict biotope.  I've terraced 2 to 4" of gravel, and laced it thoroughly with Laterite.  I followed the advice of my LFS and mixed 2 liters of peat pellets in with the gravel and laterite. <Hmm, not something I'd do, I don't think; I prefer to have peat in my filter where I can remove it if I so choose.> The problem:  My pH was too low, 5 to 5.5 <Zowie!> and the water was yellow.   <To be expected, when you use peat and/or bogwood - running carbon in your filter may help remove the yellow/brown stain.> So I emptied the whole tank and tried to rid of much of the peat, and I got a lot of it out, maybe a third of it.  Now that a day has gone by the yellowness is much less but the PH is still 5 - 5.5.  PH from my tap is alkaline, about 7.5.  What should I do to get the PH to the 6.5 - 7 range?    <There are lots of buffering materials on the market; one that comes to mind is made by Seachem I believe, and comes in a green-labeled clear bottle, the product itself is pink.  I don't for the life of me recall the name of it - perhaps Acid Buffer or Discus Buffer.  This might be something to try, if your water hardness is very low, as I suspect it is.> Is there any way other than to break it down and manually remove the peat, pellet by pellet?   <This reminds me of childhood days, when I liked nothing better than to sort nuts from bolts in my Dad's garage....> Or perhaps easier, just get rid of the whole gravel bed and start afresh, this time with very little or no peat? <If you do this, go without peat in the gravel, for sure.  You don't want to put something in the substrate that you may have to remove - as you surely understand now, it's a very undesirable task.  Addition of peat in the filter(s) is far and above a better way to go about it, in my opinion.> Or should I just go with it as is?  To me it seems that PH is too low. <It is (though there ARE some fish that would like it), and by the sound of it, is unstable as well, yes?  My vote - either remove the substrate and redo, remove the peat from the substrate (have you got any children that might be talked into such a task? lol), or perhaps try a buffer to raise the hardness of your water to keep the pH a touch more stable, and livable.> Thanks for your comment. <Any time, Jeff.  Wishing you well,  -Sabrina> Jeff Zegas

Low pH question Crew- <person> I've read your faq on PH, and I've asked around at every LFS in my area, >however, I've got a problem with low PH.  In most of my tanks, the PH has gradually dropped to 6.0 or 6.2.  I've tried PH up (works for an hour or so, then drops by the next day), <indeed... they are always temporary for pH> I've tried adding small amounts of baking soda (works for about a week, then drops back to the "usual" level).   <also temporary for hardness unsupported> No ammonia present, nitrites 0, nitrates within acceptable levels, temp 78.  Existing fish seem happy and fine, however, I cannot add new fish to the tank safely.  I've tried slowly adding tank water to the bag to acclimate them, but 80% of the time, they die within 24 hours.  These are fish from different stores, and if I were to add them to my tanks that don't have a low PH, they would be fine.  I do 10% water changes every week, vacuuming the bottom.  I do have a small amount of driftwood in the tank for the pleco's to munch on, <no problem> lots of live plants - and to make things more difficult, fry in a "fry saver" net - so I'm very wary of drastic changes and adding chemicals to try and adjust anything.  Water from my tap comes out around 8, settles after a day to 7.6.   <whoa... that right there is very telling! Stored water that decreases in pH indicates high levels of CO2 in the home. And that is assuming this is stored and sitting. If the water is aerated (and it should be!) the pH should go up! My advice is to do a simple test to confirm this. Take a sample glass/bucket of aquarium water and test the pH before and after a 12 hour aeration period. If the pH rises in this sample after 12 hours of aeration... you have a CO2 problem (accumulating). This either means that you don't have enough circulation in the tanks... Or... the house/room needs better air circulation (for you and the fishes). I proffer this beyond the obvious candidate (which I have ruled out, perhaps unfairly, with the assumption that your LFS was smart enough to rule this out for you or that you discovered it in the FAQs)... which is that your tap water is simply soft (under 200ppm... worse if under 140ppm). Soft water is unbuffered and cannot maintain pH for very long. To correct you simply aerate (first) then buffer (Seabuffer products) tap water before you use it for the fish tanks. Do a hardness test of you tap and aquarium waters> I'm only having PH problems in my 29, 20 and 20long tanks, the 10s are all fine - cruising around 7.0, 7.2.  I hope I've given enough information, any tips?  More frequent and/or larger water changes? Jennifer B. <as per above, my dear. Do follow up with result/questions as needed> ps: I had checked the buffers in tanks once, and if I'm remembering correctly, there was none (does that sound right? it was a while ago). <Good that you've checked... but I doubt your recollection is correct. If your "buffers"/Hardness were zero... the LFS should have noticed that immediately as the problem. That would mean that you have extremely soft tap water (which can be very good for many south American fishes if it is buffered up just enough to be stable. Angels, tetras and discus will love this. Most catfish too>

Malaysian Driftwood, pH Reduction Hello. <Scott F at your service> Where I live the pH is high; therefore, the pH in my 10 gal tank is also high. <Just how "high is "high"? It may be acceptable, depending upon the kinds of fish that you keep> Someone suggested that I purchase some driftwood since it would help lower the pH in my tank, but I should let it soak since the wood would tint my water until the water becomes clear. Is there any way to speed up the process of getting rid of the brownish water?  <Activated carbon in your filter should do the trick. Using driftwood, peat moss, etc. to lower pH may be hard to control-much depends on the rate of dissolution of the tannic acids, etc. present in the wood. If you are dead set on lowering the pH, you may want to use one of the prepared products designed just for this purpose > Are there any other "natural" ways to lower the pH in a high pH area?  <Do read this faq: "pH, Alkalinity, and You" in the freshwater articles section of wetwebmedia.com> Thanks, Rachel <And thank you for stopping by!>

Re: PH I would like to lower my PH in my tank. For some reason it always stays at 8.4 I would like to bring to 8.2 or 8.3. People are telling me to use proper PH 8.2 but I would rather not use a chemical is their another way to do this? What is the cause of ph being high is their anything I should test for. <Mmm, a few ways. Need to know "why" (what your water constituents, make up is) in order to say more specifically... If it's a common case of high natural carbonates, bicarbonates, I would blend in some reverse osmosis (softer) water, just let time go by... aquariums tend to "go acidic" with time... and you can balance this drop with changing out part of the water on a regular basis. You may need to learn about  alkalinity, its relationship to pH, get/use a test kit for alkalinity. Please read here: http://www.wetwebmedia.com/acidalkph.htm> Be chatting. Bob Fenner>

BGA. Hi Bob, I am currently fighting an outbreak of the dreaded BGA in two of my Freshwater planted aquariums. Everything was fine until I was forced to move the 45 gallon aquarium from one side of the room to the other. I have done similar loads of times before with out any trouble. After the move everything seemed to settle down nicely and within two days I went back to my usual regime. The stock of fish were as follows: 10 Wild Emperor Tetras, 5 Silvertip Tetras, 8 Albino Corydoras (Aeneus), 1 Adult Angel and 5 Clown loach. After 3 months I have lost 1 Clown, 3 Emperors, 4 Silvertips and 5 Corys, I also have a small growth of BGA which is starting to spread slowly. Having read your article on the drawbacks of Anti-Biotic in the aquarium I have hoovered out as much as possible and have performed a 20% water change. My question: What do I do now? <A few possibilities... increase aeration and/or circulation, increase lighting intensity, duration (maybe check on the age of your lamps), measure nutrient make up of your water... keep vacuuming out the bits you find... Add carbon dioxide to your water (do you have infusion?)... Bob Fenner, writing about brackish plants as we key>

RE: BGA. Thanks for the prompt reply, my lighting is on for eleven hours daily on timer with new lamps, I am not using Co2 but I am contemplating going in this direction as my PH is about 8, circulation is via Eheim 2313 thermo filter. <Yeeikes... 8.0! I would use the carbon dioxide trick... a great boost all the way about, including battling the BGA. Bob Fenner>  

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