how to lower pH to blackwater levels and keep it there?

[anasteso1454]

All of you guys and girls who have experience with blackwater species, here is the question of the day for you: how to acheive a ph of about 5.5 and keep it stable?

I have heard: peat filtration, indian almond leaves, pressurized CO2 injection, etc.

tank is 2 gal nano, planted tank
HOT 3 stage filter
GH approx 100-120, average
KH approx 1-2 (residual, no buffer added)
pH approx 7.5, average
NH3-, NH4, NO2, NO3 all 0, average
50% water change weekly

I know that if I can add enough CO2 to drop the pH to 6.0 at KH of 1 or less that the CO2 concentration would be about 15+ mg/L (ideal). I prefer not to have to rig it up to my CO2 tank on my large system b/c I would have to move the tank...any ideas??

[MatsP]

Lowering the pH if the water is hard can be tricky (and 100-120 ppm is fairly hard).

But the real trick is keeping it stable at that low pH.

I'm afraid I don't really know the answer to your question, just that "it's difficult".

I don't know of many fish that actually require really low pH - most are absolutely fine at 6.0 or higher. Going lower than that requires "dangerously low KH".

--
Mats

[sidguppy]

you DO know that blackwater does NOT support plantlife and that by lowering the pH into blackwater range you will kill all your plants?

[sunfish]

2 gal and blackwater, so we're talking Parosphromenus here? Or what do you want to keep?

Your water is a bit hard, so first you should try and get it softer. The softer the water the easier to maintain very low pH. To do so I'd use a type of peat filtration. Just putting peat into your filter works (in a way), but you won't get stable water parameters. Each water change will change softness and pH in the tank.

Instead, use peat to filter all new water that goes into the tank. Depending on the parameters you're after you can then mix this "peat-water" with unfiltered tap water to generate the hardness you want. Thus you can add water with the same softness and pH as in the tank.

[Richard B]

Some basics...

The larger the artificial body of water (ie fishtanks) the easier it is to keep stable - inversely the smaller, the more difficult. 2 Gallon is tiny. Creating something such as pH 5.5 for a stable period is difficult enough but in that size is gonna be IMHO more trouble than it is worth - what is the objective behind this?

[anasteso1454]

well I am well aware that the volume of water is inversly related to how difficult it is to maintain any pH level, but no, I was not aware that a pH level of 5.5 would not support plant life. I had looked up pH ranges for the plants I have (at www.tropica.com) and found that they should be able to handle 5.5 as the "bottom edge" of their pH range.

as a matter of truth, I am actually already keeping Parosphromenus deissneri as well as Paracheirodon axelrodi. My goal in all of this is to breed the Parosphromenus and have heard that they are found naturally with pH as low as 4.5 (though that is way below what any plant I know of can handle, thus my goal of 5.5 so far).

my goal is 70-90 ppm. Right now it is around 120 ppm. What I have read about these species is that Paracheirodon really prefer GH between 1-5 and Parosphromenus between 1-8 dGH. A word of clarity would help here (I hope). I measure ppm with a tds meter which measures conductivity of ALL ions, rather than just using a test kit to measure calcium and magnesium, and then converting to ppm. So if 120 ppm = 6.7 dGH that could be understood as medium hard water based on concentration of calcium and magnesium compounds. However, I can say that nearly ALL of the tds comes from plant fertilizers that I add to the water, so I wonder if the water can really be considered hard???

If so, I suppose I should just remove all/most of the plants and just make this a breeder tank for the parosphromenus??

I am not assuming to be an expert, just working based on what I know so far. Someone please tell me if I am about to do something stupid!

[L number Banana]

Hi, I'm not someone who can advise expertly in anything yet - still learning but I wanted to ask one thing first - what the hardness of your tapwater?
Next, try rainwater, I keep three barrels in the basement for my tanks. Melted snow in the winter.

Let me tell you about my 33gal tank and you may get some ideas that will work. I keep mine at 6.5 and have to add tapwater to bring it up from 6 about every two weeks. It was as low a 5.5 last week after medicating for ick. Maybe you could tweak my system to fits your needs? My plants all grow lush and green and bloom like crazy and the fish are happy? and spawning etc. It's pretty regularly a half point drop in ph and I've heard swings of more than that can be bad for your fish.

-Back substrate is Black flourite, front is white silica sand.
-Add 5 ml liquid carbon (Flourish Excel Liquid Carbon) every day if I remember.
-No fertilizer other than fish poo etc. Substrate is high in iron and never needs replacing. I don't vacuum through the roots and flourite substrate, only the sand gets a tussle to make sure there's no hydrogen sulfide bubbles stuck in there.
-I add a beech leaf here and there maybe once a month when I notice that the old ones have disappeared.
-Bi weekly water change unless I got a bit crazy with feeding, then weekly at about 25%.
-El Cheapo Whisper filters hang on the back with floss and bio filter. Never "cleaned", just banged out on the edge of the sink when the flow decreases, every month or so?
-Air stone bar always going at night when the plants are using oxygen.
-Water's finally nice and clear after much dicking around and no algae other than the occasional crop of Black beard algae that I get rid of with a syringe of the liquid carbon if it's in a spot that bugs me.
-No ammonia, nitrate or nitrites.

Don't know if any of this gives you some tips or ideas but it works for me.

I would look up "PH crash" on some of the fish sites just so you know what to look out for. I almost happened to me once but I caught it in time and didn't lose and fish. Maybe one of the experience members could chime in on what a ph crash really is? I only know mine dropped a full point in a day after a bacteria/protazoa bloom -maybe because of it? Still don't know.

Good luck with the tank

[Shane]

tank is 2 gal nano, planted tank

As you are well aware, maintaining a stable "radical" pH (in this case a blackwater environment) will not be easy in such a small container.

On the positive side... it will be much easier to create blackwater in such a small container as you need only a very small volume of soft water. In your case a 50% weekly water change with a gallon of distilled water or rain water with a small portion of tap water added for buffering is all you will need.

my goal is 70-90 ppm

This is actually quite hard. True blackwaters I have measured would be under 1 ppm hardness. The distilled/rain mixture above should put you around 1-2 ppm, which will work well and a add a slight buffer as a safety net.

-Shane

[sunfish]

Parophromenus actually require very soft, accidic and nearly sterile water for reproduction. And they prefer dark tanks. Thus, using peat to filter the water is good on all levels, as this will also turn the water brown and add certain "chemicals". This mimics the water they're found in in the wild quite well. If you don't wat to mess around with peat (it is a bit messy) you could also use peat extract.

Here is a good article from a German aquarist on how to keep and breed Parophromenus. The Google translator isn't perfect, but you should be able to get most of the information.
http://translate.google.de/translate?js ... l=de&tl=en

[anasteso1454]

well it seems that what I really want to do is to set up a separate breeder tank and make it a true blackwater tank. Somehow it never occured to me that in order to get to a true blackwater environment I would not be able to keep aquatic plants (or at least, to fertilize them) because the GH would never drop low enough.

What I am trying to do with the current setup I guess is just to keep the parosphromenus and paracheirodon but not to breed them in that tank, because I want to keep the plants. The nano is actually my wife's tank and she is quite attached to her aquatic plants! (so she will have to let me set up one more aquarium now...heh heh)

So I just want to keep the water as soft as possible for the fish yet at the same time provide enough fertlizer for the plants. The result has been so far a ppm of around 120. I had medicated the tank about a month ago so it is possible that this is still reflecting some residual tds from the medication (it shoots up to over 600 ppm when you add a tablet form of medication such as Lifeguard). I would expect it to drop further as water changes continue.

I was always under the impression that in the grand scheme of things a ppm of 70-90 is actually considered soft water, though of course compared to actual blackwater environments it would be quite hard.

does anyone know how to sex these fish? I am not sure I have an actual pair!

[apistomaster]

I'm keeping 24 Poeciliocharax weitzmani aka Black Darter or Black Morpho Tetras and 15 Parotocincinclus cf. epplyei in water with a pH of 5.5 and TDS about 25 ppm. The water temperature is 82*F. I have good growth of Flame Moss and Java Moss on the wood I provided and on the one of the sponge filters. I also have a thriving potted Echinodorus parviflorus var "Tropica" which has a single NutriFin PlantGrow spike timed release fertilizer buried in the potting material which is the same as my bottom substrate.. I also threw in a hand full of fallen dried Cherry Tree leaves as leaf litter and to help lower the pH. When you use mostly RO water in the presence of decaying organic matter the pH easily will fall below 6.0 without adding anything specifically to lower the pH. Keeping Poeciliocharax weitzmani is not easy but similar in many ways to Parosphronemus spp. My Poeciliocharax weitzmani are fed only live Grindal worms and small live blood worms. My "black water" set up is a 20 gal L, 30 X 12 X 12 inches. Substrate is a thin layer of Coralife PlantGro less than 1/4" deep.
I use an Aqualight dual 30" T-5 NO 21 watts each lamp Fresh Water lighting strip.

The only time i would ever consider using a 2 gal tank at these or lower values is only during a spawning attempt for something like Cardinal tetras where it is only needed temporarily. I find that Parosphronemus do better in a larger and more permanent breeding set up.

[Mike_Noren]

I've posted this before, don't mind posting it again:
http://mikes-machine.mine.nu/blackwater ... g_tank.htm

I link to Ron Lasts very interesting article towards the end, but it's in Swedish, here's a (not too hilarious) google autotranslation:
http://translate.google.com/translate?u ... n&ie=UTF-8

[anasteso1454]

wow thanks for all the good advice everyone! I am certainly not new to the freshwater hobby but I am new to blackwater, esp breeding those species, so this whole process is an exciting learning experience!

you learn something new every day.

[L number Banana]

anasteso1454 wrote:

you learn something new every day.

Makes me want to try a blackwater too!

The nano is actually my wife's tank and she is quite attached to her aquatic plants! (so she will have to let me set up one more aquarium now...heh heh)

You already have the important things figured out

[racoll]

I think in your situation anasteso1454, I would experiment!

People tell you all kind of things based on common knowledge, assumptions or experience. In these kind of situations though there are so many variables involved, you just have to try for yourself.

I run an office nano with almost neat RO water (tiny bit of tap added to about 10 ppm). I have a huge lump of wood in there and the water is dark. The pH was about 5.0, but is now about 6.5 (for some reason) and quite stable. The plants grow nicely, and grew even better when the pH was about 5.0.

How valuable are your Parosphromenus? Can you afford to lose them?

I would start experimenting, using almost neat RO or rainwater combined with peat. Mike's link would be a great place to start.

[dw1305]

Hi all,
I'd agree with Apistomasters comments, black water species normally require low pH and low TDS to breed successfully. Many aquatic plants will grow at pH 5.5, but at these sorts of levels they will all be plants with very low potential growth rates, so fertiliser or CO2 becomes irrelevant. I'd go for peat filtered rainwater (or R.O.), silica sand substrate, dead Oak leaves and a planting with lots of "Java" moss, if it works for Apistogrammas I don't see why it shouldn't work for other fish. You will need to change water regularly as nitrogen cycling is inhibited at low pH, and you don't get much "biofilm" development. I'd probably go for 20% daily as it is such a small tank.
cheers Darrel

[apistomaster]

Hi Darrel,

I agree with everything you said but biological filtration continues to work well enough at very low pH ranges in normal sized tanks. Nothing works very well in 2 gallon tanks compared to larger aquaria.
I think what happens in black water or other very soft and acid water aquariums is that other species of nitrifying bacteria carry out the normal nitrogen cycling. I have a lot of experience with keeping Heckel Discus for years in water with a pH of 5.0 or even slightly lower and a TDS around 20 ppm. Some of my more experience Altum Angel keeping friends routinely keep them at a pH of 4.0 to 4.5 and only 15 ppm. If biological filtration did not work they would have to be able to change much of their water daily and provide some aeration and dispense entirely of the biological filters but they don't.
That said, any change involving an already established biological filter should be brought about very gradually; basically in the same way one would acclimate the fish. I don't think the new class of organisms are as efficient as those that do best in much less extremely low water values but over loading any black water type aquarium is particularly unwise since the fish evolved to live in such waters are not well adapted to coping with high bacteria counts nor much nitrate of any kind. It is best to stock any black water tank at much lower levels than many may be used to for a typical community type tank as most people conceive them.

[Jon]

I wouldn't worry so much about H...fish are reasonably adaptable in this regard. For fish which hail form these environments, total softness (or rather, lack of conductivity in general) seems to be a far more important issue. RO.

[apistomaster]

I wouldn't worry so much about H...fish are reasonably adaptable in this regard. For fish which hail form these environments, total softness (or rather, lack of conductivity in general) seems to be a far more important issue. RO.

I feel the same. When maintaining very low conductivity(Low TDS), the pH will drop anyway and to me having the pH go down gradually due to a lack of buffering capacity the process is more gradual and easier on the fish. deliberately lowering the pH through the use of chemicals tends to cause more problems than their worth. Having peat or leaf litter present contributes weak organic acids which lower pH gradually and more gently for the fish.

I checked the progress in my 20 Long, black water, Black Darter Tetras / Parotocinclus sp 3 tank yesterday and I have never added any acid buffer but I did use some dried Cherry tree leaves and have been continuously lowering the conductivity. The pH has now reached 4.8. TDS was 40 ppm, higher than I expected at this point. I'm shooting for 15 to 20 ppm.

Just an aside: A tip about electronic pH meters. They usually have a cap which is supposed to contain water to keep the electrodes wet but that water tends to dry up fast. I now use blue masking tape to seal the cap from evaporation and use the low end 4.01 calibration water for long term storage. I have gone a couple months without using the meter and the tape maintained a tight seal and prevented any evaporation. The blue masking tape works well because it doesn't leave any adhesive residue and may be reused a few times. The electrodes of pH meters cost almost as much as a new meter and it is bad to let the electrodes to become dry. If you are delving into keeping fish that do best at very low pH values an electronic meter is the only way to fly. I use a Sharp Water Proof Electronic pH Meter.

[dw1305]

Hi all,
Hi Larry, I haven't really escaped from "Apistogramma forums", I just need to post occasionally on PC (where I've lurked for long time), or my membership is culled, and I have to re-join. Yes I think you are right about nitrogen cycle, I always keep planted aquaria, and I'm a bit of a fanatical water changer, so I've never really found out what happens when you rely on the nitrogen cycle, but tank volume would be much more of an issue for me as well. Why are posted this reply is Larry's point about pH meters is really important.

Just an aside: A tip about electronic pH meters. They usually have a cap which is supposed to contain water to keep the electrodes wet but that water tends to dry up fast. I now use blue masking tape to seal the cap from evaporation and use the low end 4.01 calibration water for long term storage. I have gone a couple months without using the meter and the tape maintained a tight seal and prevented any evaporation. The blue masking tape works well because it doesn't leave any adhesive residue and may be reused a few times. The electrodes of pH meters cost almost as much as a new meter and it is bad to let the electrodes to become dry. If you are delving into keeping fish that do best at very low pH values an electronic meter is the only way to fly. I use a Sharp Water Proof Electronic pH Meter.

Drying is a major cause of failure in pH meters, we are very careful in the lab, and store the electrodes in 3M (molar) KCl (potassium chloride) sol. When the meters are in day to day use, we use parafilm (bit like clingfilm) to seal the caps, between uses. We also re-calibrate the meters on the buffers every time we use them, and make sure they have been turned on for 10 minutes before we buffer and take a reading.

cheers Darrel

[Jon]

recalibrating pH meters is one of the great banes of my existence.

[grokefish]

Hi, I'm not someone who can advise expertly in anything yet - still learning but I wan.................................."Stuff".........................................................................................................
...............................................................full point in a day after a bacteria/protazoa bloom -maybe because of it? Still don't know.

Good luck with the tank

I love your approach to fishkeeping L, I rekon it is the best way to keep fishy's happy!