ph of 4.3... how? identical large tank reads 6.0

[JackBlasto]

I have two tanks. One is 120 gallons and one is 29 gallons. In my 29 gallon tank the ph is LOOOOOOW... 4.3 The EXACT same water that goes in the big tank is 6.0. All I can think of is the substrate is different and causing the difference? The tank with a low PH (29 gallon) has a gravel substrate from back in the days when I didn't know any better. I have read that gravel can trap things that would lower the ph. SOoooo, that said I have gravel siphoned that tank at least 50 times over and its water comes out crystal clear in hopes I have got all the debri and STILL the ph is lower. Now, why the heck would this be???

Any thoughts? Thanks

For the record I have just calibrated the PH tester and still question it but all side tests read seemingly appropriate.

 

[Mebbid]

Both of those ph readings are terrible.. what's the ph of the water when it comes out of the tap and after it sits out overnight?

How much surface agitation is there in the tank with the lower ph?

 

[JackBlasto]

Well 6.0 for Discus ain't terrible... but 4.3 certainly is Out of the tap is 7... Back to the question though... why would this be? There is driftwood in both tanks and both are planted.

 

[Mebbid]

The only problem is that at 6.0 all beneficial bacteria activity stops.

Whats the kh of both tanks?

 

[dalto]

The only problem is that at 6.0 all beneficial bacteria activity stops.

Are you sure about that Mebbid? That doesn't match my experience. I have kept quite a few tanks in the high 5's and have still had nitrate production and ammonia consumption. It has seemed like the number at which it stops in my tanks was closer to the lower 5's.

 

[Mebbid]

There was a large scientific study I read on it a while back. I lost the link but I could dig it up again if you want. It stated that our bb slowed down at 6.5 and stopped completely at 6.

 

[JackBlasto]

I'd be interested in reading more about it. I mean I have to wonder about it for certain. Plenty of discus keepers out there keeping fish at 6.0 and if you want to test on the queen of finicky fish then its the discus, so do they not need the beneficial bacteria? Because clearly, breeders, etc are keeping discus in tanks with a low ph like that. NOW not my horrific 4.3 ph BUT 6.0, 5.8 even are discus people.

 

[dalto]

There was a large scientific study I read on it a while back. I lost the link but I could dig it up again if you want. It stated that our bb slowed down at 6.5 and stopped completely at 6.

Interesting, you would think that in a tank with no BB you would have lots of ammonium and little to no nitrates but that is not what I have seen until the pH gets quite a bit lower.

I'd be interested in reading more about it. I mean I have to wonder about it for certain. Plenty of discus keepers out there keeping fish at 6.0 and if you want to test on the queen of finicky fish then its the discus, so do they not need the beneficial bacteria? Because clearly, breeders, etc are keeping discus in tanks with a low ph like that. NOW not my horrific 4.3 ph BUT 6.0, 5.8 even are discus people.

I have no idea how you even got pH that low.

Even with tanks using pure RODI water and no additives I have never had it fall below 4.8.

Yeah, the obvious trade-off is that as pH becomes highly acidic there is no free ammonia as it is all converted to ammonium. But you have to be careful in that scenario as pH swing can cause serious havoc as the ammonia quickly becomes toxic.

 

[JackBlasto]

I


I have no idea how you even got pH that low.

Even with tanks using pure RODI water and no additives I have never had it fall below 4.8.

Neither do I! I'm freaked out! I do a RO/Tap mix... 50/50... comes out at 6.8 (just retested) and after the RO is added and it sits in the reservoir it goes into the tank at 6.0

Anyway, I am thinking it has something to do with low KH that caused the PH to crash. I mean thats my only logic here. My KH tested low. about 1 so that said its possible that the KH was so poorly buffered the tank dropped into that. I have been doing 20%-30% water changes daily (with my 6.0 reservoir) and we will see what happens.

I mean the parameters of 6 I am fine with for Discus but the 4.3 is not ok. Discus in that tank are eating and acting normal and healthy too so I have no idea how this is possible and I question my reader but I have done a separate liquid test which caps out at 6.0 sooooo, I have no way of verifying how low below 6.0 it is with the liquid test. I have read that breeders and some wild caught are in ph's as low as 4 so I'm guessing this is possibly why... I mean the fish MIGHT be happy... it just scared ME and I'm really scared the KH is not going to hold up.

 

[PNWaquarist]

Do you live near a coal mine? I know that industry is pretty big in WV and the effects of acidic runoff have been well-documented.

Even pH 6.0 tap water is really low. It sounds like you may need to add baking soda or some other substance to both raise and buffer your pH.

EDIT: Just saw your message about your tap water being pH 6.8. That's not a problem. Are you just getting set up or are your tanks old?

 

[dalto]

Is your KH 1 out of the tap or just in your tank? If that is your tap value than you will have issues and my want to use a phosphate buffer that will keep pH low. If that is just in your tank than larger, more frequent water changes should resolve the issue.

 

[PNWaquarist]

Yeah, that KH is too low. Phosphate buffer or baking soda will work. Both will also raise the pH a little, which will help combat "old tank syndrome."

I have a less extreme problem, with a KH of about 2.5 degrees. My pH recently dropped from the usual 7.3-7.4 to closer to 7.0. I measured the KH this morning and it was down to about 2. I added 1/4 teaspoon of baking soda to about 2 cups of tank water, stirred, and added half of that back to the tank. Twenty minutes later, my pH was back up to about 7.4 and my KH was somewhere between 2 and 3. Problem solved.

 

[mrvincent]

For the record I have just calibrated the PH tester and still question it but all side tests read seemingly appropriate.

LOL [Moderator edit]... What's the KH° of that water ?

Is this water sparkling water ?

My KH is 2, and the water stuffed of CO2 is at 6.6...

My RODI water is at 6.3-6.4... I don't understand... Maybe your kit is VERY VERY VERY bad. I already had a cheap digital PH tester, and it was giving me bad results... One day PH4, the other PH of 7 for my FW tank... One day it gave me a reading of PH6 for my REEF :O I suggest you use a high range test kit (Bromotymol blue) or maybe a low range 6-7.5 test kit...

I don't consider your readings as serious until you test with chemicals. Your LFS can test it. 10 bucks for this test kit and worth it!

Also before you run to the LFS to get PH-Up, I advice you: DON'T MESS WITH THE PH TONIGHT!

 

[trennamw]

Absolutely sounds like you need some buffer. What pH are you aiming for?

I tend to suggest cichlid buffer (which has baking soda and something else) which for me had been more stable than baking soda or the acid/alkaline buffer combos. But it and baking soda may make your pH too high if you're keeping discus.

I've kept identical tanks that always had different pH too. Dunno.

What is your GH, just out of curiosity?

I have experience getting extremely soft water (KH and GH of <0.1) to stay in the sevens for a community tank with easy fish. But if you need soft water and a low pH I'd suggest you follow the advice of people who supplement RODI water for discus. You'll get a lot of different opinions here but some may not match your needs.


Sent from my iPhone with three hands tied behind my back.

 

[trennamw]

I wouldn't add pH up at all unless you're very very sure it's the right solution. I tried that and it led to worse swings and higher tds, with no upside. The pH just kept going back down.


Sent from my iPhone with three hands tied behind my back.

 

[mrvincent]

Make sure of the REAL PH before doing anything. Test with a high range chemical test kit and we'll tell you how to correct your water if there's a need to.

PH of <5 seems to be a bad test kit or bad reading for aquarium water IMO.

 

[JackBlasto]

One tank is very old... 10 plus years... large tank relatively new... as in 2 years.

I'm really believing it was the result of a KH issue and I'm hoping I have it under control with some serious water changes... Now I am thinking about the no beneficial bacteria addition to the discussion... One is do beneficial bacteria simply cease production at 6.0 OR do they continue to exist and simply don't produce? Meaning if I dumped in BB from a third party are they all dying or do they simply exist and don't multiply?

 

[dalto]

Doesn't the high range pH kit mentioned above only test pH above ~7.4? I think the regular pH test from API is the one you want. It 6.0-7.6 is I remember correctly.

As far as I know there are no liquid or strip tests that can go lower than 6. I use a digital meter for that.

 

[J.Mcpeak]

If you change enough water it should match the source, sounds like old tank syndrome. Just carry on with regular water changes. It should balance itself in a few weeks.
Simply put, Kh/GH become depleted in a sealed environment with biological activity.

From experience something like 30% twice weekly normally see things stay normal but this will depend on stock, substrate, plants, volume, photoperiod, etc. all these things can have an effect pH. or it's stability.

Change things slowly and the filter bacteria can adjust to the changing conditions.

 

[PNWaquarist]

If you change enough water it should match the source, sounds like old tank syndrome. Just carry on with regular water changes. It should balance itself in a few weeks.
Simply put, Kh/GH become depleted in a sealed environment with biological activity.

From experience something like 30% twice weekly normally see things stay normal but this will depend on stock, substrate, plants, volume, photoperiod, etc. all these things can have an effect pH. or it's stability.

Change things slowly and the filter bacteria can adjust to the changing conditions.

I agree. You may want to SLOWLY ramp up your KH and pH with baking soda (to a KH of maybe 3 degrees, and whatever your tank pH corresponds to at that point). After that, weekly WCs will be needed to maintain your KH (and you may need to occasionally add to that).