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Buffering RO water

17K views 43 replies 3 participants last post by  maxw47 
#1 ·
How should I go about buffering RO water? I get how to add the minerals and such back, but the buffering part is confusing me. I'd like to stick with seachem products. I think I would be using their neutral regulator, acid buffer, and alkaline buffer. All that I can tell from reading about them online is that you're supposed to add acid and alkaline buffer in order to get the desired pH, and neutral regulator to buffer that (up the KH) and keep it from shifting around. I am assuming that more specific instructions are on the product labels themselves. Am I right on this? As of now, I am only keeping lots of plants and breeding some platies, so I'm looking for a pH of 7-7.5 and a Kh of say 4-5 (sound right?) Would I just add some alkaline buffer to get to a pH of 7.5, or nothing for a pH of 7. And then add a certain amount of neutral regulator to get me to my KH of 4-5? Please put in what you know and thanks for any advice!
 
#3 ·
I agree. Mixing varous chemical preparations can get troublesome, and very expensive. Knowing what fish you intend keeping would help us suggest better alternatives. Also, can you use some tap water mixed with the RO? What is the GH, KH and pH of the tap water?

Byron.
 
#4 · (Edited)
We have a water softener that uses sodium. I guess the sodium ions aren't very good long term for the fish and plants. I only have platies right now and they seem to be able to handle it alright. The plants don't like it though. Even with a good substrate, decent lights, and co2, they grow slow and the tank gets algae. I had some panda cories that didn't do well too. I want to start keeping some more sensitive, soft water species too.
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#5 ·
We have a water softener that uses sodium. I guess the sodium ions aren't very good long term for the fish and plants. I only have platies right now and they seem to be able to handle it alright. The plants don't like it though. Even with a good substrate, decent lights, and co2, they grow slow and the tank gets algae. I had some panda cories that didn't do well too. I want to start keeping some more sensitive, soft water species too.
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I agree that softeners using sodium can be worse than the hard water for soft water fish. The livebearers are better able to tolerate salt, but as you say, plants may not.

My suggestion here would be to use a calcareous substrate in the tank with livebearers (only) and plants. Crushed coral and aragonite blend sands are ideal. Another member pointed out a glitch though, and that is during water changes. But here I would suggest you use water pre-softener, assume it is on the hard side? You might even manage with this without the special substrate. Livebearers need medium hard to hard water, with a basic (above 7) pH, and there are many plants that will thrive in this--Vallisneria for one.

For the soft water aquarium, use RO water and add Equilibrium (a Seachem product) to raise the GH sufficient for the plants. Soft water fish do not need any of this, but they will be fine. I have near-zero GH and KH tap water, and only for my plants do I use Equilibrium to raise the GH to around 5 or 6 dGH. The pH will remain acidic. With regular water changes, there should be no issues. I never mess with KH, as I have seen no pH problems.

Byron.
 
#6 ·
Thank you so much! I found some info on seachem's acid buffer and alkaline buffer. Have you ever used these? I know that you said that you don't like to mess with the KH, but I think that I am going to use the acid and alkaline buffer to get a KH of 2-4 or so. I am going to have CO2 running on all of the tanks and I don't want a pH crash. Should I worry about that? I'd like to stick with the seachem products, and adding them to the RO water before water changes, only so that I know what my KH and pH will be, because I don't know how to regulate that if I had let's say crushed coral. Do you see what I mean? Again, thank you so much!
 
#7 ·
I need to know a lot more before I can comment beyond what I've already suggested. What is the GH, KH and pH of your tap water before it goes through the softener. You can get the GH and KH from the water supply folks, they may also know the pH. And I assume you would be able to obtain this water (pre-softener)?

A pH crash is highly unlikely in a planted tank with balanced fish load, weekly 50% partial water changes, and not overfeeding. In my 20 years of dealing with very soft water out of the tap, I have had tanks with the pH below 5, and tanks with the pH in the 6's. I only keep soft water fish, and this has never been a problem.

Byron.
 
#8 ·
Here are the params before the water softener-
-pH: 8.2
-GH: 7
-KH: 11

This is all making more sense now. I was just nervous because I had heard stories and what not about peoples pH crashing after starting to add CO2, and it turned out their KH was really low. But their tanks were probably under different variables. All of my tanks (hopefully) are going to be very well planted and have a healthy amount of fish. But let's say that I sold all of the fish in a fry tank, or I transfered a lot of plants from one tank to another, leaving it lightly planted. At that point, would the tank be vulnerable to a pH crash? Has anything similar happened to you? I am not really that worried about this, but I just want to know. Thanks again for so much help!
 
#9 ·
Here are the params before the water softener-
-pH: 8.2
-GH: 7
-KH: 11

This is all making more sense now. I was just nervous because I had heard stories and what not about peoples pH crashing after starting to add CO2, and it turned out their KH was really low. But their tanks were probably under different variables. All of my tanks (hopefully) are going to be very well planted and have a healthy amount of fish. But let's say that I sold all of the fish in a fry tank, or I transfered a lot of plants from one tank to another, leaving it lightly planted. At that point, would the tank be vulnerable to a pH crash? Has anything similar happened to you?
Not likely, and no, to your last two questions. Let's see if I can explain a bit. First, the water parameters of the tap water, meaning GH, KH and pH, will tend to remain the same in an aquarium up to the point when biological actions occur, as will happen in any tank with fish. Organic waste increases, and the breakdown by bacteria creates CO2 which adds carbonic acid to the water, lowering the pH. The KH acts as a buffer, and the higher the KH the less pH will fall. This is very general. Other factors affect all this. The more substantial the water changes, the more stable things will be. Live plants will use CO2 and nutrients from the organics breakdown. Not overfeeding will keep the waste less. And so forth.

It is possible to have the pH lower so far that certain fish are affected. Our profiles give pH ranges for each species. Regular weekly 50% partial water changes in my experience prevent any serious problems with this.

To your water params, the GH at 7 dGH [presumably this is degrees] is good. The pH is high, and the KH at 11 dKH is likely to keep it there. As you now have and use RO, I would experiement with mixing pre-sopftener water with RO. Try half/half and see where the GH and pH fall. You might find this article helpful:
http://www.tropicalfishkeeping.com/freshwater-articles/water-hardness-ph-freshwater-aquarium-73276/
 
#10 ·
I should have mentioned this to you earlier, but I don't really have access to the pre-softened water. I have tried all of the outside spigots and everything inside the house, and they are all connected to the softener. So I can't really mix the RO with it and get good stuff. All of this making more and more sense now. If these tanks were dirted (dirt substrate w/ gravel on top), would that effect the pH? Plus the CO2, my pH would probably be brought down significantly. You mentioned crushed coral, aragonite, etc earlier. Would you recommend having a filter bag (one of those fabric bags that filter media is held in) with like crushed coral in the filter or in the sponge filter bubbles. Do the buffering qualities of crushed coral change over time? Again, a tremendous thank you for your advice!
 
#11 ·
The advantage to using the pre-softener water is cost savings; no need for expensive mineral additives if you can make use of what is naturally in the water. Pity that won't work for you.

This puts you in a very similar situation to me. My tap water is near-zero GH and KH, less than half of one degree for both. Which is fine for soft water fish. But insufficient calcium and magnesium for plants. So I use Seachem's Equilibrium to raise the GH to around 5 or 6. This provides the calcium for the plants, but does not impact the fish or mess with the pH. This stuff is expensive, but you can buy it in a tub online which makes it much less costly over time.

The problem with crushed coral is that it sends the pH sky high while adding very minimal hardness and buffering. I have tried it in my canister filter, half a cup in a mesh bag. I also tried the coral/aragonite mix, same problem. Dolomite worked better, if you can find it. But with RO water none of these will add sufficient "hard" minerals for plants.

What is the pH of your RO water which you are now using? Does it lower much in the aquarium from week to week?

Byron.
 
#12 ·
Right now I am still using the well water, unfortunatly it's softened. But hopefully I can get the RO rolling in under a month. I do however already own a small container of equilibrium. It probably won't last long, but enough to get me started. So I have my GH under control. But for platies at least, I would need to bump up that pH. How would you suggest doing that? The crushed coral, aragonite, etc. doesn't really sound like a good idea. Have you ever kept fish with similar requirements? I think the acid/alkaline buffers by seachem would work, but from what you have said, that doesn't sound good either (by the way, thank goodness you are here or else I would have resorted to this kind of stuff). Would something like a little bit of baking soda work well? I would just add a little bit to my water change water every week. The only thing to figure out would be just how much. Any thoughts? Thanks!
 
#13 ·
For livebearers, you must be more drastic. Here I would use an aragonite-base sand as the substrate. I did this many years ago with dolomite gravel (all that was available back then) and it worked very well. My mollies thrived, as did Vallisneria which likes hard water. I've no idea what the GH was then, I didn't measure or know anything about it in the 1980's,:lol: but the pH stayed up around 8 which was perfect. Here again your pre-softener water would be ideal on its own. You can buy mineral additives for fish [Equilibrium is better for plants] but again they are costly. The corla/aragonite blend sand is a few dollars for a bag, CarribSea make a couple of types, there are probably others. Just make sure it has aragonite in with the coral, as the aragonite adds the magnesium to the calcium.

For the soft water fish, as I said, there is really no issue once we get the plants satisfied. Rainwater also works well, it is very soft and usually on the acidic side. If you can collect it, that is a good source water for soft water fish.

Baking soda is not good, long-term. It will not buffer in the face of continuing acidification, and it adds no mineral value for plants or fish anyway. I think I mentioned this in that article. I know Dr. Stan Weitzman wrote on this, and he carried out considerable scientific study at the Smithsonian and recomended against using sodium bicarbonate (baking soda).

Byron.
 
#14 ·
All right, so let me get this strait. Aragonite based sand for the livebearers plus the equilibrium to target a GH of six or so. Sound right? Could I have a mesh bag of the aragonite/coral in the filter? Or would that be less effective? I wouldn't want to change a bunch of substrate if I didn't have to. But no problem if not. As for the soft water fish, no buffers and keep a GH high enough to sustain the plants. And no baking soda in any tanks. Does this all sound good? Thanks!
 
#15 ·
I suggest you keep livebearers in their own tank, and soft water fish in another, don't mix them [probably what you said, just want to make sure;-)]. This will make it much easier.

For the livebearers, just use the calcareous substrate, problem solved. Water changes can be less volume to avoid fluctuating parameters. As my experimenting showed, with soft water anything less is inadequate. The substrate lasts for years.

For the soft water fish, RO or rainwater, with Equilibrium to raise the GH up to 5 or 6 for the plants.

Byron.
 
#16 ·
Sounds good! Now I guess all I have to do is make some money! This stuff is expensive. One more question though (it seems as if there is always something to learn). Should I not run CO2 in the livebearer tank(s)? I probably wouldn't have a great plant substrate anyways, so it would most likely just create an inbalance, or in other words algae. But I am good to have CO2, dirt, and high lights in the softwater right? How far would this stuff bring the pH down from 7 considering there are minimal buffers?
 
#17 ·
Diffused CO2 in the soft water system would lower the pH. Probably quite a bit, given the no GH, no KH water. This is where you could see a crash. Are you actually planning CO2? Assuming you intend soil, this is intended to provide more CO2 at least initially; it has no other real benefits [others can disagree with me all they like:argue:, the proof is in the pudding].

In the livebearers, no CO2.
 
#18 ·
Ok. I did have some DIY running a while ago, and id did help. But I've seen some great tanks without it, the soil should cover it, and it just seems like more work than it's worth. Would the soil pose any danger to a crash? How much would it lower the pH?
 
#19 ·
Difficult to say. The water chemistry and biology of an aquarium is very complex. I don't know how many times I have read from more experienced sources that it is risky to fiddle with any aspect of the water, say pH, because there is such a complex relationship covering many facets of the water chemistry, and adjusting this or that can have repercussions.

On soil, I frankly do not believe it is worth the risks. I admit I have never tried it--but one does not have to jump off the cliff to know it is dangerous.;-) CO2 naturally occurs in the substrate be it soil, sand, gravel. The benefit of soil is getting more CO2 initially due to the organics and bacteria already present. With a plain sand or fine gravel substrate, organic waste has to accumulate and bacteria begin to break it down. While this takes a few weeks, in my experience from setting up dozens of tanks with new substrate I have never had the plants fail, but they take longer to get going. But during this period, the fish are adjusting to the environment too, and everything is developing naturally. With soil, it is common to have ammonia at very toxic levels, and this can last for months. Many recommend a "dry" start, and then no fish in the tank for six months. Given the fact that after say a year the soil tank will have no benefits over a plain sand or fine gravel substrate tank--what is the point of doing it?

If you check the photos of my tanks in my log [click "Aquariums" below my name on the left] you will see what my method produces. Keep it simple, there is less to go wrong.:)
 
#21 ·
I've tried one enriched substrate, Flourite, and found it disappointing. It cost a lot, $180 compared to $14 for playsand for the same sized tank. I've had it in my 70g for 19 months now. I would not waste the money. My plants (same species, under the same light, with same fertilization) in the sand and gravel tanks are doing just as well. Now, having said this, I have read that some of the newer substrates are better. But still seems a money pit to me. Another issue is substrate fish, some will not do well over these because they are angular and a bit sharp. I had to remove my corys from the 70g, and I would never have loaches in this. I'm planning on tearing this tank down one day and replacing the Flourite with sand; I have the sand, just getting myself geared up to washing it.:lol:

Quikrete Play Sand from places like Home Depot or Lowe's is very inexpensive and works well; I now have it in 5 tanks. Liquid fertilizers are sufficient; I do also use substrate tabs in 2 tanks but only for the larger swords plants and the Tiger Lotus lilies.

Byron.
 
#22 ·
That helps a lot. Another trap I would fall into if it wasn't for you! Should I be take caution on how much aroganite sand I put in the tank? For eample, if the tank was ten gallons, should I put 10 pounds in? That's what I do with other substrates.
 
#23 ·
I go by the depth. You probably want about 1.5 to 2 inches overall (by which I mean the depth of the washed sand across the entire tank floor after you dump it in and before aquascaping). I have this in my smaller tanks. In the 115g I probably have 3 inches. Then you can slope it with less at the front (1 inch is fine) and more at the back where the larger-rooted plants will be. Heavy chunks of rock can be used to build up deeper levels, though frankly they tend to level out over time anyway. This applies to the aragonite sand in the livebearer or the inert playsand in the other.
 
#25 ·
You're very welcome. Don't hesitate to ask us questions, ever. That's why we're all here, to help each other.:)
 
#27 ·
Most plants will manage in harder water. Corkscrew Vallisneria is just one that really does better in harder water, and it is a lovely plant; check the profile. Also browse the others, the water params are given where this is important. Off the top of my head, I can't imagine any of the commonly-available plants not coping.

On the light, what fixture do you have? Be specific (if fluorescent tubes, what is the tube length), and what is the tank length?
 
#29 ·
On one of the ten gallons, I have just one T8 tube, 20 inches. The other has 2 compact flourescents.
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Both are fine. With the fluorescent tube, find one with a Kelvin around 6500K, anywhere between 5000K and 7000K is good. I like the Life-Glo 6700K by Nutrafin or the UltraSun 6500K by ZooMed. In T8 obviously, the T5 (which won't work in your fixture) are getting common.

For the screw-in, two 10w Daylight 6500K CFL bulbs. I use the GE, but Sylvania and Phillips also make similar. Just make sure it is the 6500K, might take a bit of looking as these are ot as common as the warmer CFL's. And 10w is plenty.

Byron.
 
#31 ·
I don't know. When I bought my 29g with hood, it came with an Aqueon tube which I sent to recycling and replaced with the Life-Glo. But over a 10g, and if this is the same type (no idea), it may be fine. Does it give a purplish hue, or cool white like the 6500K tubes/CFL?

Tubes have to be replaced every 12 months, they lose intensity as they burn and after 12 months are too dim to be sufficient. I find the Life-Glo can go longer, maybe 18 months, because they are better made.
 
#34 ·
It will raise it, but how much I can't say. In the livebearer tank this won't really matter, since those fish need this hard mineral.
 
#36 ·
You won't need Equilibrium for plants if you have calcareous sand for the substrate and this will add calcium and magnesium. Flourish Comprehensive will then supply the other nutrients sufficiently.

In the soft water tank you need Equilibrium to add sufficient calcium and magnesium.
 
#38 ·
You probably have it. "Flourish" is the name of a line of products. Under this name it will read "Comprehensive Supplement for the Planted Aquarium" in smaller black print. Other products will read "Excel", "Potassium" or whatever. You want the Comprehensive.
 
#41 ·
Wood, peat, leaves etc release tannins which tends to acidify the water and lower pH. However, the amount of wood plus the GH and KH of the water will play into this so it is again variable. If you have a calcareous substrate (the coral/aragonite sand mix) a few bits of wood will have no impact.
 
#42 ·
Okie dokie. While I put the new substrate and change out the water in the main ten gallon, would it be a good idea to move the fish to the fry tank? The fry tank is ten gallons and only has 4 little platy fry in it big enough to not be eaten. I would move the HOB filter from the main tank to the fry tank temporarily as well. And once the main tank is set up with new water, substrate, and plants, I'll aclimate the fish back into the tank like I would if I just bought them from the LFS. Sound good?
 
#43 ·
Yes. I always remove all fish to a temporary tank when I do major work like removing the substrate.
 
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