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Discussion Starter · #1 ·
hello, i have very hard tap water, and I'm sick of it and have finally decided to go with a RO unit
which will be arriving be arriving soon, being new to RO i have a few questions.

i will be setting up a nature aquarium and would like
my Ph to be neutral/slightly acidic for the plants as well as fish species
so as RO strips the water of all minreals leaving a Kh of 0 and Gh of 0 as with a neutral PH
what product can i use to bump the GH and KH to optimal levels (4-6 GH, 4 KH) whilst also maintaining a neutral/slightly acidic Ph.
i would prefer to buy a pre made product. and have looked at a few however they all seem to raise the ph.

thanks
 

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Adding KH will raise pH. Best thing to do is get a GH only booster and use a buffering substrate which will lower the pH and buffer it to keep it stable. However, buffering substrates do exhaust over time and then you'll either have to adjust for that or replace the substrate. If you use water that has KH, the substrate will strip it anyways but by doing that it will exhaust the buffering ability quicker.
 

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Discussion Starter · #3 ·
what about if i was to use somthing like "SaltyShrimp Aquarium Mineral GH/KH+" and get my GH to 6 and my KH to 3,
would that be ok for a heavily planted aqaurium is there a optimal gh/kh.
 

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what about if i was to use somthing like "SaltyShrimp Aquarium Mineral GH/KH+" and get my GH to 6 and my KH to 3,
would that be ok for a heavily planted aqaurium is there a optimal gh/kh.
Yeah...that's fine...but the KH will raise your pH. To what...I don't know. But it will. That's what I use in my shrimp tank...it's good stuff.
 

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For my planted tanks I use Seachem Equilibrium to raise the GH, Seachem Alkaline Buffer to raise the KH, and then Seachem Acid Buffer to get the pH where it needs to be.
This is a great way to go. Then use the on-line Seachem calculator to dial in what you want. Their technical support by phone is second to none.
 

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However, buffering substrates do exhaust over time and then you'll either have to adjust for that or replace the substrate. If you use water that has KH, the substrate will strip it anyways but by doing that it will exhaust the buffering ability quicker.
Be VERY careful about “buffering” substrates. They are usually carbonates and will raise KH (stabilizing, but countering acidic pH levels). Recently, I had a very bad experience with Seachem’s Onyx Sand. Seachem claims that it will slightly buffer the tank. However, it raises KH significantly for quite a while (3 months, so far) and, more importantly, turns your tank into a hard water tank. They do not warn customers about this! My RODI water starts the week at about 1 dGH (after a 60% wc) and rapidly (3 days) climbs into the 10 dGH area because of this “slightly buffering” substrate. Of course, with injected CO2, the 6.4 pH dissolves the Onyx Sand at good rates. If you want acidic and soft water. Avoid buffering substrates.

For my planted tanks I use Seachem Equilibrium to raise the GH, Seachem Alkaline Buffer to raise the KH, and then Seachem Acid Buffer to get the pH where it needs to be.
My experience with Seachem Acid Buffer is that it works for a very short time - a day at most. There is really no way to safely and consistently reduce pH into the acidic area unless you add CO2.

Any of the GH buffers, Seachem Equilibrium, NilocG GH Booster, etc can be used to adjust GH to your liking for the RODI water. You can also make your own Ca/Mg mix.
 

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i will be setting up a nature aquarium and would like
my Ph to be neutral/slightly acidic for the plants as well as fish species
so as RO strips the water of all minreals leaving a Kh of 0 and Gh of 0 as with a neutral PH
what product can i use to bump the GH and KH to optimal levels (4-6 GH, 4 KH) whilst also maintaining a neutral/slightly acidic Ph.
i would prefer to buy a pre made product. and have looked at a few however they all seem to raise the ph.

thanks
Is there any reason you want to raise KH? 99% of plants really could care less about KH (the other 1% wants none of it). The tank crash everyone talks about...? Never seen it or had it happen to me.

GH would be more important to plants and tank inhabitants. When you hear this fish likes soft water they are not talking about KH, instead they're referring to GH.
 

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How are you using Seachem Acid Buffer? When used to adjust down the pH of RO water after it has been raised using Alkaline Buffer it works just fine. I'm not adding it to tap water.

Equilibrium raises the GH of the RO water (I raise it to about 3 GH). It also adds minerals needed for plant growth.

Alkaline Buffer raises the KH of the RO water (again I raise it to about 3 KH).

Alkaline Buffer also raises the pH so you add Acid Buffer to get the pH where you want it to be based upon how much Alkaline Buffer you added. I add enough to adjust my pH to 6.5.
 

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Is there any reason you want to raise KH? 99% of plants really could care less about KH (the other 1% wants none of it). The tank crash everyone talks about...? Never seen it or had it happen to me.

GH would be more important to plants and tank inhabitants. When you hear this fish likes soft water they are not talking about KH, instead they're referring to GH.
Because KH buffers water to prevent pH swings. Pretty important when you have livestock in the tank.
 

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Because KH buffers water to prevent pH swings. Pretty important when you have livestock in the tank.
Oh, I get it. If you have no KH, PH will plummet to death levels. I hear it all the time. I've just never seen it or had it happen. Calcium carbonate is not the only buffer we see in tank water.
 

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Pretty sure that 1000's of people that use substrates such as ADA or Tropica or Stratum don't have issues. They do exhaust but they don't cause problems as you describe.
Yes, you're right: those substrates don't cause "buffering" which is generally considered to mean raising KH. However, you said "buffering" and, so, I wanted to warn against seeking a "buffering" substrate when the OP is looking to have low pH and somewhat soft water environment.
 

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Be VERY careful about “buffering” substrates. They are usually carbonates and will raise KH (stabilizing, but countering acidic pH levels). Recently, I had a very bad experience with Seachem’s Onyx Sand. Seachem claims that it will slightly buffer the tank. However, it raises KH significantly for quite a while (3 months, so far) and, more importantly, turns your tank into a hard water tank. They do not warn customers about this! My RODI water starts the week at about 1 dGH (after a 60% wc) and rapidly (3 days) climbs into the 10 dGH area because of this “slightly buffering” substrate.
If the substrate is calcium carbonate or magnesium carbonate KH, GH will increase Because the CO2 you are injecting into the tank will cause the carbonates to dissolve. However in a low tech tank with No CO2 injection the GH KH and will stay at about 1 and the PH will stay at 7. This is bacause calcium and magnesium carbonates only dissolve in acidic water. Once the PH drops to 7 it stops dissolving.

Adding sea shells or crushed coral to your filter will do this nicely in a low tech tank and would allow you to use a totally different substrate such as black diamond blasting sand. Even with the low GH and KH I never had a PH crash. Note sea shells or coral are mainly are about 90% calcium carbonate. Dolomite is a mineral that is about 50% calcium with the reset Magnesium. Dolomite has some advantages over sea shells and coral. With water that is mostly calcium carbonate it is possible to have a magnesium deficiency develop. Dolomite is more balanced so that makes magnesium deficiency unlikely.

Most products sold to boost KH are potassium or sodium bicarbonate. these will dissolve at any PH allowing a greater increase KH but they will also increase PH. The best way to achieve what you want is to use a mixture of tap and RO water. Most of the KH in hard water is from calcium and or magnesium carbonate. However if the PH suddenly dropped it would not counteract the PH drop if no solid carbonate is in the substrate or filter. So I would a mix of RO and tap and also put sea shells or dolomite in the filter and to not use CO2 injection.
 

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You can most definitely do it! I do it and use seachem's acid and alkaline buffer. These two will allow you to adjust your ph and kh to whatever you want. Then get a gh booster from GLA or nico, which contain just what the plants need. You can also cut your RO water with treated tap water so you require less buffer. My tap is liquid concrete, so I had to go this route for my planted discus tank and it is working out wonderfully. PM me if you have any questions about the process. It really is not hard and seachem also offers great support!
 

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Discussion Starter · #17 ·
thanks everyone for the help,

but what about top offs?
should i add 100% pure RO or should i add reminrealised RO for top offs?
 

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You replace any evaporated water with pure RO, as that's what would have evaporated - all the minerals are left behind in the tank so topping up with just RO keeps the right balance :)
 
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