Seachem Buffers & RO Right

[Eryn]

Hey Tom or anyone who wants to help,

I'm in Burlingame and I'm on the San Francisco water system. I keep mostly low-tech planted tanks, one CO2 ADA-style tank, and a lot of unfiltered, medium-plant-mass betta tanks which I change 100% every week or so. I've always buffered my water to raise the KH while keeping the pH between 6.5 and 7.0, and I've pretty consistently stuck to Seachem's buffer products (previously Neutral Regulator/Discus Buffer; now Alkaline Buffer/Acid Buffer). I've also been using "RO Right" by Kent to add GH (I breed bettas and it was suggested to me that their fins grow better with sufficient mineral content).

Qualifier: People have often given me the advice that I shouldn't be messing with buffers, the simpler the better, tap water is fine, etc. But I've always felt I needed a buffer because otherwise the pH would be hugely variable -- the pH would start out quite high (7.8+) from the tap and drop over time in the tank (down to 6.0 and lower, depending on how long between water changes, plant vs. fish load, etc.). I have some soft-water fish that don't prefer pH above 7.0, and I didn't like shocking any of my fish during major water changes by adding high-pH tap water to a tank that had become pretty acidic over time. I killed quite a few otos that way, before I started buffering.

Two things recently changed that make me question my buffer use. First, I've noticed that the tap water is no longer 0-1 DH like it was a while ago—it's more like 6-8 DH. Now that the tap DH is closer to 7, maybe I don't need to add RO Right anymore. But I feel I still need some kind of buffer or the pH will swing like I described above. What do you all do?

Second, I've noticed that after I add the buffers to replacement aquarium water during a water change, the pH in the bucket is about 6.5. This is right where I want it. But after a few days in the aquarium, the water is closer to 7.5 or higher. Why is the pH rising? This has been happening in all my tanks, including the unfiltered betta tanks, low-maintenance tanks, and the CO2 tank (though the CO2 tank doesn't rise quite as much, because of the CO2).

This didn't used to happen before when I was using only Neutral Regulator/Discus Buffer, no GH additive (no RO Right), and the tap water was 0-1 DH. Back then, the bucket would be 6.6-6.8 pH and the tank water would stay in that range long-term. (BTW, I switched to Acid/Alkaline buffer rather than Neutral/Discus because Neutral Regulator supposedly softens the water by precipitating out Calcium and Magnesium, which would make my addition of RO Right useless.) Now I'm using Alkaline Buffer/Acid Buffer, RO Right, and the tap water is 7 DH -- so which of those three is the culprit that's raising my pH over time?

In case it matters, this is what I add to every 5g of my replacement water during water changes:

3/4 tsp Acid Buffer
1 tsp Alkaline Buffer
1+ tsp Ultimate conditioner
1 tsp RO right

Thanks for any input!

Eryn

 

[Tom Barr]

They gave you good advice

It's fine if you want to do more work and spend more $. That's your choice crtainly. But the argument over pH is mute.

It really does not matter to the fish, the KH, not GH so much, is the main variable.

When you measure pH during the light peroid also makes a big difference, in the non CO2 tanks, pH's of 7-8- even 9 are normal if you have plants in there, or a lot of algae maybe.

KH is the main thing that will control pH, but pH in and of it's self can move around depending on the % of CO2, which has nothing to do with any buffers you add etc, it's indepedent. That's why p does not matter to fish in CO2, just the KH and whether it's stable.

They likely switched to Crystal spring water for now since the lake is full, they will switch back to Sierra snow melt later. They tend to mix some higher KH/GH water sources to buffer pipes for corrosion control during seasonal changes to keep the alkalinity (KH) up for many of the drinking water processes. Their source changes during snow/rain events, so they modified it accordingly.

Ours also changed here in Sac, American river water is similar to SF's Hetch Hetchy.

I've never bothered with wasting my time, $ or labor fiddling with pH, KH etc, unless I wanted less KH. Then I'd use RO and blend with the tap to get the KH I wanted.

Having bred many fish, often inadvertly, shrimp, kept Altums and other sensiive species..........I see no reason to adjust these parameters.

GH booster is the same as SeaChem Eq, and baking soda adds KH.
You need no other chemicals for adjusting KH/GH and indirectly, pH via KH.
Once the tap degasses, and equilibrates, the KH/CO2 from the air controls the pH.
But oftn times, under pressure, and cold, the tap will have high CO2. This degasses later, the your pH goes up.

Buffers will not stop that either.

In other words, do not fall for the pH myth, pH is justa proxy for many other things that may be going on. I'd not rely on it much, TDS, KH etc, stick with those.

Regards,
Tom barr

 

[Eryn]

Thanks, Tom, for the quick response. All your experience is certainly quite a help... I'm just not quite sure if I can bring myself to believe that pH doesn't matter. Especially after (as a newbie) having killed fish with large water changes of greatly different pH but exactly the same KH.

I do understand the chemistry you're referring to, about the KH and CO2 deciding the pH in a CO2 tank. But some of my fish do really want a certain pH --- for example, I'm keeping clown killies in a non-CO2 tank and want them to breed, which they won't do above 7pH --- so I'm not so sure pH is irrelevant. Or maybe you mean that it's the KH that decides things, and if I can get the KH right, then the pH will follow?

I'm not so concerned about my CO2 tank. I'm mostly concerned about my non-CO2 tanks containing softer-water (under 7-8 DH), lower-pH fish like killies, badis, threadfin rainbows, etc. Could you tell me what I'd need to do to the KH in order to to achieve a stable, soft, low-pH environment for them? I've always thought that the higher the KH, the less the pH fluctuates. But is it possible to have a reasonable KH and yet the lower pH they require?

So the pH was rising because of outgassing... very interesting. I thought for sure I was adding too much buffer or RO right. So basically if I want to use buffers (of course I'd rather figure out another way to get the parameters right, but just for argument's sake...) I'd have to let the water outgas before adding buffers and then re-measure how much of each buffer I need to add to achieve the desired pH/KH. Right?

Thanks Tom! Your sharing is greatly appreciated.

Eryn

 

[Tom Barr]

Well, years of plying the issue with pH from LFS's, books etc, German's loved to measure water, it's a hard myth to break, but few in water treatment will say otherwise.

Alkalinity is what buffers pH change. Baking soda does that as well as anything for our purposes.

If you want lower KH(Not sure what DH is, might be GH, which is Ca and Mg only, KH is HCO3 which typcally makes up all the Alkalinity in FW systems- but not always), I'd just use peat or RO water blended to get whatever KH you want, say 2 degrees or so.

Regards,
Tom Barr

 

[Eryn]

Thanks, Tom, all good advice. I think I'm going to wean my tanks off of buffers.

Still, I'd like to better understand the relationship between buffers and pH and KH. I did a few measurements again tonight and found that the Burlingame tap water has gone back to 0-1 KH. (btw DH is "degrees of hardness," a way of measuring GH.) Here's what I found for new tap water, aged tap water, freshly treated water, and aged treated water:

New, chlorinated (and chloramine) tap water: KH=0-1, GH=0-1, pH=7.8+ (off my chart)

20-hour aged, aerated, dechloriniated tap water: KH=0-1, GH=0-1, pH=6.8

Freshly buffered water (with buffers, dechlorinator, and RO right): KH=5, GH=6, pH=6.5

Buffered water from a betta jar (one fish and a small clump of java moss) that I changed 100% a few days ago: KH=5, GH=6, pH=7.2

So, that leaves me with a few questions:

1. Why does the KH of the unbuffered tap water start high and get lower after outgassing/aging?

2. The tap water's KH is already super-low, so why is the pH at 6.8 instead of lower?

2a. If I wanted to keep a fish that was generally known to appreciate a pH of, say, 6.2, what would be the best way for me to achieve a good environment for this fish, considering that the KH is already about as low as it can go?

3. Why does the buffered water's pH rise significantly after such a short time?

I'm just really curious about the chemistry...

Your insights are greatly appreciated!

Eryn