Low pH, gH and kH from tap

Hello! My 25 gallon dutchscape tank has been cycling for almost 2 weeks. I tested the waters recently and saw that the gH = 3 dgH, kH = 0 dkH and pH = 6. My nitrates and nitrites looks good. I want to add some amano shrimps, siamese algae eaters, and some tetras in but was afraid that the gH, kH and pH were too low. So I added some seachem Equillibrium with Acid and alkaline buffers to target gH of 6, kH of 8 and pH of 6.5. I tested the next day and it all checks out, but my TDS was reading 1450ppm. Isn’t this way too high for fish and plants to grow?! What should I do???
My tap water reads gH = 3 dgH, kH = 1.5 dkH and pH = 6. Are there any ways to raise gH, kH and pH without raising the TDS? I’m aiming for TDS of 150-200ppm as I believe this is a good TDS for plants and fish to grow. Let me know of my thoughts are wrong and any tips!
Thanks!

 

Most fish and plants do fine in a wide range of kh (1-10dkh) and same with gh. The exception being certain species like live bearers and African Cichlids which would not do well in a low kh/gh environment.

First, are you using fresh aquasoil with a buffering capacity? If so, 0kh is nothing to be feared as the soil will buffer it to avoid "ph crashes". With your fish selection honestly a kh of 3-5 and gh of 4-6 is fine which is what I would aim for. I don't think you need a kh of 8. Adding less kh/gh buffers will lessen the spike in TDS. Also, how long after adding the remineralized RO did you wait to test TDS? I've realized that if you test immediately after it will throw you a crazy number. When I first switched my dutch tank to RO I tested TDS immediately after adding my ferts and gh/kh booster and got around 400 which was hard to believe. I tested it the next morning and got a TDS of 75. I'd try and retest TDS and make sure your TDS meter is calibrated.

Equilibrium doesn't add anything to boost kh. To simplify this for you I would suggest getting salty shrimp kh/gh+ or nilocg's kh and gh booster instead. I use the nilocg and I like it because it's a ready to use liquid. I don't use the pumps however I just 5ml pipettes to measure out the liquid when I remineralize. I keep my dutch tank kh 0-1 and gh 3-4 for caridina shrimp. My plants and betta are fine.

 

TDS is not a good measurement because it measures EVERYTHING. KH, GH, NH3/4, NO2, NO3, humic acids, salts, ions... simply everything that's dissolved in the water So unless you know each part separately the TDS readings tell you... well, nothing.

For most tropical fish low readings for KH, GH and pH are no problem. As said above livebearers are out, as are Rift Lake cichlids and rainbowfish, when the water is very soft and acidic. Additionally most invertrebrates need at least a significant GH, otherwise they are unable to build their shells and exosceletons due to lack of calcium. pH below 6.5 also tends to dissolve at least the outer layers of snail shells.

gH of 6, kH of 8 and pH of 6.5

Sorry, but this is physically impossible. With a KH of 8 the pH will stay way above 7. You might reach 6.5 with a KH of less than 4 and the addition of enough humic substances.

 

Most fish and plants do fine in a wide range of kh (1-10dkh) and same with gh. The exception being certain species like live bearers and African Cichlids which would not do well in a low kh/gh environment.

First, are you using fresh aquasoil with a buffering capacity? If so, 0kh is nothing to be feared as the soil will buffer it to avoid "ph crashes". With your fish selection honestly a kh of 3-5 and gh of 4-6 is fine which is what I would aim for. I don't think you need a kh of 8. Adding less kh/gh buffers will lessen the spike in TDS. Also, how long after adding the remineralized RO did you wait to test TDS? I've realized that if you test immediately after it will throw you a crazy number. When I first switched my dutch tank to RO I tested TDS immediately after adding my ferts and gh/kh booster and got around 400 which was hard to believe. I tested it the next morning and got a TDS of 75. I'd try and retest TDS and make sure your TDS meter is calibrated.

Equilibrium doesn't add anything to boost kh. To simplify this for you I would suggest getting salty shrimp kh/gh+ or nilocg's kh and gh booster instead. I use the nilocg and I like it because it's a ready to use liquid. I don't use the pumps however I just 5ml pipettes to measure out the liquid when I remineralize. I keep my dutch tank kh 0-1 and gh 3-4 for caridina shrimp. My plants and betta are fine.

Thank you for the info and tips! My tank was setup with ADA Power Sand Advance with Amazonia Ver 2 on top … not sure if that’s useful info regarding the aquasoil buffering. I’ll do a wc later to lower the TDS and will retest the next day. Will I be able to add neon dwarf rainbowfish into my tank with the parameters you recommend?

 

Thank you for the info and tips! My tank was setup with ADA Power Sand Advance with Amazonia Ver 2 on top … not sure if that’s useful info regarding the aquasoil buffering. I’ll do a wc later to lower the TDS and will retest the next day. Will I be able to add neon dwarf rainbowfish into my tank with the parameters you recommend?

Yes they will be fine at that kh/gh level but go to the high side of the range I gave you. But why are you concerned with TDS anyways? TDS doesn't matter much at all unless you are either keeping caridina shrimp or its stupid high (like above 500)

 

TDS is not a good measurement because it measures EVERYTHING. KH, GH, NH3/4, NO2, NO3, humic acids, salts, ions... simply everything that's dissolved in the water So unless you know each part separately the TDS readings tell you... well, nothing.

For most tropical fish low readings for KH, GH and pH are no problem. As said above livebearers are out, as are Rift Lake cichlids and rainbowfish, when the water is very soft and acidic. Additionally most invertrebrates need at least a significant GH, otherwise they are unable to build their shells and exosceletons due to lack of calcium. pH below 6.5 also tends to dissolve at least the outer layers of snail shells.


Sorry, but this is physically impossible. With a KH of 8 the pH will stay way above 7. You might reach 6.5 with a KH of less than 4 and the addition of enough humic substances.

I see! Maybe because I used seachem Acid and Alkaline buffers together, I was able to reach the pH and kH, just TDS crazy high so I was wondering if I should even bother adding Equilibrium, Acid/Alkaline buffers and just go with the water parameters from my tap (just add Prime), considering the fishes and shrimps I want to add, is it still ok?

Yes they will be fine at that kh/gh level but go to the high side of the range I gave you. But why are you concerned with TDS anyways? TDS doesn't matter much at all unless you are either keeping caridina shrimp or its stupid high (like above 500)

I just heard that fish grow well and are less stress with lower TDS, so crazy high numbers aren’t good and might shorten their life. And plant growth slows down if TDS is also high since they won’t be able to absorb nutrients. Not sure if thats right but I think I read it on 2Hr Aquarist or some other forum. Let me know if this is true

 

I see! Maybe because I used seachem Acid and Alkaline buffers together, I was able to reach the pH and kH, just TDS crazy high so I was wondering if I should even bother adding Equilibrium, Acid/Alkaline buffers and just go with the water parameters from my tap (just add Prime), considering the fishes and shrimps I want to add, is it still ok?

I just heard that fish grow well and are less stress with lower TDS, so crazy high numbers aren’t good and might shorten their life. And plant growth slows down if TDS is also high since they won’t be able to absorb nutrients. Not sure if thats right but I think I read it on 2Hr Aquarist or some other forum. Let me know if this is true

If you want to keep the rainbows then no, you would have to remineralize your tap. Like MacZ said praecox rainbows need a kh of 2-6 and gh 6-12. So again, kh of 3-5 and gh of 4-6 is where you want to be for most fish with certain exceptions.

 

If you want to keep the rainbows then no, you would have to remineralize your tap. Like MacZ said praecox rainbows need a kh of 2-6 and gh 6-12. So again, kh of 3-5 and gh of 4-6 is where you want to be for most fish with certain exceptions.

If kH at 3-5, what is the pH level in order to have neon dwarf rainbowfish?

 

I see! Maybe because I used seachem Acid and Alkaline buffers together, I was able to reach the pH and kH, just TDS crazy high so I was wondering if I should even bother adding Equilibrium, Acid/Alkaline buffers and just go with the water parameters from my tap (just add Prime), considering the fishes and shrimps I want to add, is it still ok?

If you want shrimps you have no choice but adding something, at least for GH.
Rainbowfish (e.g. M. praecox or M. lacustris) usually need a pH above 7.5, but that comes automatically with KH (Both are connected unseparably, with KH determining the pH if unaltered by addition of acids or bases.)

But why are you concerned with TDS anyways? TDS doesn't matter much at all unless you are either keeping caridina shrimp or its stupid high (like above 500)

Agree. TDS is just useful if you keep especially softwater or even blackwater animals. Then TDS shouldn't rise above a certain (low) level. Otherwise measuring TDS is a good idea to look after the state of an RO membrane, but there practical applications end pretty much.

 

If you want shrimps you have no choice but adding something, at least for GH.
Rainbowfish (e.g. M. praecox or M. lacustris) usually need a pH above 7.5, but that comes automatically with KH (Both are connected unseparably, with KH determining the pH if unaltered by addition of acids or bases.)


Agree. TDS is just useful if you keep especially softwater or even blackwater animals. Then TDS shouldn't rise above a certain (low) level. Otherwise measuring TDS is a good idea to look after the state of an RO membrane, but there practical applications end pretty much.

So should I be concentrating on my kH, gH and pH readings and ignore the TDS? So if my kH, gH, pH, ammonia, nitrites and nitrates all checks out, but TDS high like 500+ is still ok for tetras, amano shrimps … right?

 

So should I be concentrating on my kH, gH and pH readings and ignore the TDS?

Yes. Or rather: Just don't measure TDS.

So if my kH, gH, pH, ammonia, nitrites and nitrates all checks out, but TDS high like 500+ is still ok for tetras, amano shrimps … right?

No. That's not the right conclusion. It all depends on the singular readings.

And also: Together they should not even reach that level.
E.g. a reading of 5° for GH, is about 90mg/l of calcium and magnesium, 5° KH about 90mg/l of carbonates. Now add 20mg/l of Nitrate and let's say 10-20mg/l for everything else combined and you get to about 200-250mg/l TDS. mg/l and ppm are interchangeable.

 

Yes. Or rather: Just don't measure TDS.

No. That's not the right conclusion. It all depends on the singular readings.

And also: Together they should not even reach that level.
E.g. a reading of 5° for GH, is about 90mg/l of calcium and magnesium, 5° KH about 90mg/l of carbonates. Now add 20mg/l of Nitrate and let's say 10-20mg/l for everything else combined and you get to about 200-250mg/l TDS. mg/l and ppm are interchangeable.

I see! Thank you so much for the tips and just clearing out a lot! I’ve learnt a lot! Now i have a sense of what to be looking for!