GH/KH, pH and Seachem Neutral Regulator

[H2Ogal]

I don’t have a test kit for GH/KH so took a sample of my tap water to an LFS. Tried to find info online to decipher the results, but no luck. Can someone please explain these to me?

KH 4.2 and Alkalinity 1.49 using Salifert kit
GH 1.72 using API test

My tap pH is 7.2. In the tank, it rises to 7.4 or 7.6 within a day or two and keeps going up. I’ve had it as high as 8.0-8.2 after a week. It also drops easily. I added ketapang/Indian almond leaves after a big WC/rescape, and it went from about 7.4 to 6.2 in less than a day.

Current occupants are otos, a ramshorn and Malaysian trumpet snails. I plan on adding a betta, rasboras and kuhlis and had wanted to use ketapang leaves with them, but I don’t want to have the pH zooming up and down.

The LFS sold me Seachem’s Neutral Regulator and said it takes the pH from either high or low toward neutral (7.0) and help to hold it there. According to Seachem’s website, it’s phosphate based and works by precipitating calcium and magnesium. (Also says it removes chlorine and chloramine, binds ammonia, nitrite and nitrate, and stimulates slime coat production so other water conditioners aren’t needed.)

Should I be concerned about the pH swings, or does it all sound pretty normal? Should I use the Neutral Regulator? Will it really help?

 

[tackful]

Minimum recommended kh/gh values, using the API kit, are about 3 deg each. You can raise your low gh with Epsom Salt (MGS04), perhaps 1/2 tsp at a time. GH is mostly plant food, whereas KH increases your water's ability to resist ph swings, always a good thing. Each time ph changes a few tenths of a point or more, our fish must readjust part of their basic metabolism in response. If ph swings are too large, and/or occur too often, the resulting stress could kill them. That's why KH is so important, and also why it is a bad idea to tamper with our water's natural ph. Fish can adjust and thrive in a ph that is other than their so called "optimal" value, provided it is kept constant. However, when trying to raise our water's natural ph, the KH tends to resist such efforts until it can absorb no more of whatever is being added to the tank, at which time the ph may suddenly skyrocket up. if it's too high the same thing may then occurr in the other direction as you try to lower it. Enough of this bouncing ph and you may find sick or dead fish.
Don't think you would want to get caught up in this. Simply let your fish adjust to the water you have.

 

[KarlTh]

pH swings are not a problem; only swings from say 6 to 8 in a couple of hours are going to cause problems. Buggering around with the GH however (by precipitating calcium, which is the last thing you want since you've hardly got any anyway) can cause problems because that will change the TDS, which fish do find harder to cope with. That fish have to adjust their basic metabolism in response to small pH changes is not actually so; external pH is of very little consequence, as anyone who's seen their planted tank swing over a full point every day as the CO2 concentration changes will have noticed. TDS does matter because it changes the osmotic pressures over the skin, which will change the conditions in the fishes' internal fluids.

Essentially you have very soft water, which tends to be pH unstable. This can be raised by adding sodium bicarb, but you do need a KH test to know what you're doing. However, all the pHs you've mentioned are absolutely fine for fish; the limiting factor you have is that the fish need to be those which can cope with soft water, fortunately the vast majority of freshwater fish. Avoid mollies.

 

[H2Ogal]

So, if I understand things correctly, my water's soft and the buffering capacity isn't the highest, but it's nothing to worry about. I'll have pH swings, but nothing drastic enough to require buffering or pH adjustments during routine WC. Good to know.

What would make the pH in my aquarium rise? Most sources I've read (like this one) say pH drops over time, but mine always goes up. The tank had been used for 1-2 years by the previous owner; substrate is pool filter sand; API root tabs added at initial setup three months ago. Any of that make a difference?

Do GH/KH change over time in tap or tank water? Should I invest in a test kit? (I need to order some stuff from Kensfish.com, and he has the API GH/KH test for about $6.)

 

[KarlTh]

pH can rise if there's any calcareous rocks in use in the aquarium or as part of the gravel. No bad thing; it's also raising the KH.

 

[SubRosa]

One consideration with Seachem Neutral Regulator. It's a phosphate based buffer and if you try to grow live plants you'll usually wind up growing alot of algae. If you want to use chemicals to set a specific pH I suggest Seachem's Acid and Alkaline Buffer products. By mixing them together in different proportions you can set your pH where you want it. Once you have the ratio down you can determine how much of the mix to use to set the kH you want. It's too much work imo, but I used to do it when I kept Discus and started with pure RO/DI water and made it the way I wanted it. It does work really well and doesn't encourage algae growth.

 

[jpappy789]

Also, are you testing the pH at least 24 hours after it is added to the tank? CO2 in the water will gas off causing the pH to rise.

 

[H2Ogal]

pH can rise if there's any calcareous rocks in use in the aquarium or as part of the gravel. No bad thing; it's also raising the KH.

Well, the Pavestone (brand) PF sand is supposed to be 100% silica, for what that's worth. Not sure what all is calcareous.

One consideration with Seachem Neutral Regulator. It's a phosphate based buffer and if you try to grow live plants you'll usually wind up growing alot of algae. If you want to use chemicals to set a specific pH I suggest Seachem's Acid and Alkaline Buffer products. By mixing them together in different proportions you can set your pH where you want it. Once you have the ratio down you can determine how much of the mix to use to set the kH you want. It's too much work imo, but I used to do it when I kept Discus and started with pure RO/DI water and made it the way I wanted it. It does work really well and doesn't encourage algae growth.

Good point. The LFS said the phosphates used are "not the kind that causes algae" (Are there different types of phosphates?), but Seachem's site admits that Neutral Regulator can be a contributing factor in algae growth. (Currently, things are pretty well balanced. Otos are taking care of any green algae and diatoms, which I never even get to see anymore. I'm still getting a wisp or two of thread algae, but it's nothing compared to the staghorn I battled early on, so I'm pretty happy.) I don't want to adjust the pH to anything in particular — just want to be able to do WC and use ketapang leaves without the pH swinging too quickly/broadly for the fish.

Also, are you testing the pH at least 24 hours after it is added to the tank? CO2 in the water will gas off causing the pH to rise.

After adding water to the tank? (I'm not using the Neutral Regulator or anything else to buffer/adjust pH.) I've tested water straight from the tap and in the tank 24 hours later — but I haven't tested aged tap water so that might be useful info. Thanks for the idea.

 

[KarlTh]

There's only one phosphate ion, PO4-. The LFS is trying to trick you, or repeating some crap they've picked up in ignorance.

 

[H2Ogal]

There's only one phosphate ion, PO4-. The LFS is trying to trick you, or repeating some crap they've picked up in ignorance.

The latter, I believe. So many myths and miss-statements get handed around that, sooner or later, everyone falls for or repeats something that's just not right. That's why I like to double-check things, even when the source appears knowledgeable.