PH is 4.9 - What could be causing this?

[Atl300zx]

i have a 55G planted tank with Pressurized CO2 and Dry Ferts. It has a 260 watt CF but for some reason my tanks doesnt appear to be high light. Perhaps the poor design of the reflector or dirty glass tank tops.

My tanks has been doing rather well lately, most plants are growing nicely.

The issue i have however is that my pH for the past 2 months has been 4.9. This is odd, b/c i used to have a stable 6.8-7.0 pH and would set my controller to about 6.2 to get ample co2 in my tank. at first i thought my pH controller was out of calibration, so i cleaned it, soaked it in bottled water for 24 hrs, then calibrated it with 7.0 and 4.0 solution as indicated in by the manufacturer. the pH however still reads 4.9. This also means for the past 2 months i have had no Co2 being injected into my water, yet i am still getting nice plant growth

I have to trim the tropic sunset 2x a week; bacopa, wisteria, bacopa 1x a week; java moss every so often. My Alternanthera reineckii is maintaing without growing much, my vals are doing ok, the glosso is sorta dieing back slowly, the baby tears are growing slowly, the ambulia is doing ok, the crypt lutea is healthy, the dwarf sag is sending out runners (slowly), and the ludwigia is dieing, and the amazon swords are doign fine.

I blindly add 1/8 tsp CSM+B, Potassium Sulfate, Potassium Phosphates 2x a week and 1/4 tsp Nitrates 2x a week.

I get very little algae, if i forget to dose for a while i end up with green spot algae, which i think is a Phosophate deficiency.

I rarily lose fish (1-2/year) and my Cherry Barbs and Platys reproduce readily. Snails dont live long i my tank.

Does anyone have any idea why my pH is so low?

 

[rkilling1]

How often do you do PWC's?

What is the KH of your tap water?

 

[Atl300zx]

50% PWC every 10 days.

GH = 80 mg/L
KH = 30 mg/L

 

[gu2high]

What is your substrate? There must be something in the tank lead to the low pH. I guess the CO2 injection causes it. Try to turn off the CO2 for several days, then recheck pH.

Without CO2 injection, my 192w CP on 58 gallon tank will lead to algae boom very quickly. In your case, the low pH may prohibit algae growth, but I guess the CO2 level is quite high.

 

[Atl300zx]

I have Seachem Flourite.

LIke i said, with a pH that low, Co2 will not turn on. The Co2 Controller is set to 6.2, so Co2 will only be injected if the pH goes above that level. Also i have heard the solenoid click in months or seen bubbles in the bubble coutner. This means Co2 hasnt entered my tank for 2 months. I can can unplug the solenoid, but i imagine it wont change anything.

 

[newfound77951]

What kind of water do you have (ie city or well?). Do you have a softener system in your house? In my old apt we had well water and the house had a water softener. When the softener had been recently changed the water was very soft and had no buffering capacity; when the system needed to be changed I had really hard water. I ended up with pH like yours and was killing fish....ended up having to bring water home from work ("city" water) until I moved.

What is your pH out of the tap??

 

[Atl300zx]

Ill recheck the GH/KH and pH of the tap water tonite when i get home.

I have city water and i dont believe i have a water softener.

The thing that makes me believe this 4.9 has to be artifically low is that none of my fish are dieing. I even have baby platys and cherry barbs that are doing fine, which usually cant tolerate pH levels like that.

 

[rich311k]

Just curious have you test with something besides the PH probe?

 

[Atl300zx]

No, but i can. I assumed since it reads 7.0 in the 7.01 solution and 4.0 in the 4.01 solution, that is must be accurate.



Tap water readings

pH = 6.4
GH = 40 mg/L
KH = 25 mg/L

So it seems like i have acidic, soft water....it didn't used to be like this.

What can I do to bring this into the acceptable range?

Could the water quality be like this b/c we are in a drought down in GA?

 

[Purrbox]

It's not at all uncommon for the water quality provided by the city to change a couple times a year. This is why it's a good idea to check it occationally, especially when you start seeing something odd going on in your aquarium.

Personally I wouldn't necessarily recommend messing with your KH. From what I've been hearing from other people with softwater, it really isn't necessary to buffer your water to be able inject CO2. If you do decide to buffer it, then baking soda is you best bet.

 

[Atl300zx]

I have never buffered a tank before and i would like to inject CO2 again b/c my Alternanthera reineckii, glosso and ludwigia did a lot better with it.

How much would i need to add and would i just put it in the water or would i add it to my canister filter?

Some people recommend crushed coral as well in the filter, what is the difference?

 

[gu2high]

To raise pH, you can do:

Add a cup of crushed coral into the filter (if space available) or put crushed coral in a mesh bag and leave the bag in tank directly (it is easy to remove the bag). Or/and,

Add a bowl/cup-size limestone/coral in the tank. You may go to beach to pick up some coral rocks. I don't know Georgia beach but I picked up several different size ones on Florida beach when I have a very short duration there. There are so many corals on the Florida beach but I don't see them on NJ beach.

 

[Atl300zx]

I have a canister filter, so space isnt a problem.

Can crushed coral be bought at Petsmart or a speciality LFS??

I am 5+ hrs from the little bit of beach that GA has.

 

[Purrbox]

With crushed coral you don't have to dose every time you do a water change, but it's less precise than baking soda.

If you're going to go the crushed coral route, I'd recommend adding slowly to help avoid shocking your fish. Add a small amount, and then test a couple days later. If it's not where you want it, add a bit more. And so on. Slowly the crushed coral will be dissolved, and eventually you'll have to add more.

With the baking soda route, you can target a specific KH very precisely. Again you'll want to make the change slowly. Set the water change water to the desired KH using the baking soda. This will slowly raise your KH to the correct level and then maintain it as you continue doing water changes. Depending on how much you need to change your KH, you may need to start a bit lower than your goal with the water change water, then work up to it in the next few weeks.

 

[Atl300zx]

OK that makes sense.

Can someone explain the effects of low KH vs low GH on pH and how it affects the healthiness of my fish and plants?

Also why arent my fish dead with a pH of 4.6 (wht is was when i got home last night) and how my fish are reproducing and the fry doing so well?

 

[newfound77951]

Your fish have probably gotten used to it. WHen I had my pH drop, all my existing fish (except for a pleco) were fine, but whenever I added fish, they would die within a couple of days. I went through several plecos and a school of platies before I figured out what was wrong. And those aren't fish usually considered sensitive.

 

[7Enigma]

OK that makes sense.

Can someone explain the effects of low KH vs low GH on pH and how it affects the healthiness of my fish and plants?

Also why arent my fish dead with a pH of 4.6 (wht is was when i got home last night) and how my fish are reproducing and the fry doing so well?

Having a low KH means that small changes in H+ ion concentration will more drastically change the pH than if you had a higher KH (buffering ability).

GH does not affect pH. Normally higher GH water also has other dissolved solids and higher KH than low GH water, but the calcium and magnesium that make up the GH do not contribute to buffering pH swings. Basically all GH is important for is to make sure you are not deficient in the macro nutrients Ca and Mg.

So basically having a low (or very high for that matter) KH CAN negatively impact plants depending on how low the pH is and the specific species of plant. All plants have an optimal growth pH and a range around that which is acceptable. Different nutrients have solubility ranges where they become unavailable to the plant, so while they might be in your tank, the plant cannot use them. While 4.6 is quite low, it seems that your plants are still able to use the available nutrients.


Fish are very adaptable creatures and can live comfortably over a wide range of conditions, provided they are acclimated SLOWLY to those condtions. I have little doubt if your water suddenly went from 7.2 to 4.6 you would have lost quite a few, but most likely it was a slow transition that allowed them time to adapt. Several species of fish spawn at lower pH ranges, and not surprisingly this is probably an optimal pH for the fry to survive.

I have a planted tank with pressurized CO2 and my tap has a KH around 3 degrees (sorry I can't remember the ppm conversion but I think its around 15-18ppm per degree so lets say ~50ppm KH). My GH is quite high (~10 degrees), but is comprised mainly of calcium (I was stumped on my deficiency symptoms until I saw my water report). Even with all that GH my pH would swing wildly when injecting CO2 (especially because I originally started with DIY CO2).

I decided to buffer my tank with baking soda at each water change. Since I have a 20gallon I use buckets which makes buffering with baking soda easy as I can mix it in prior to adding to the tank (a python would be very difficult to keep the levels consistent during a water change). I add 1/4 tsp per 5 gallons which raises my KH about 3 degrees (if I remember correctly). This is a nice bump that keeps the pH from really dropping when the CO2 is on, and the plants/fish don't seem to mind (I did this slowly over a couple weeks). I'm actually in the process of transitioning to slightly less baking soda now since I am pressurized and don't have to worry about the fluctuation of DIY. I think you could easily go to 1/8th tsp per 5 gallons and have a safety net that might keep your plants/fish in a more optimal range. But do it slowly (say 1/8th tsp per 10-15gallons to start).

One obvious thing to mention is that baking soda and KH is a VERY sensitive thing. That means accurate measurement of baking soda is very important since such a small amount changes the KH so much. I do dose dry without a balance (which is not as accurate as liquid dosing with balance measurement) so I make sure to use completely level full scoops (I scrape the spoonful across the top of the baking soda container). This gives me reasonable accuracy that a 1/4tsp of baking soda today is the same as in 4 months.

HTH

 

[Atl300zx]

Basically all GH is important for is to make sure you are not deficient in the macro nutrients Ca and Mg.

Does this explain why snails never did well in this tank (never last over 1 month)? I have an apple snail in my 10 Gallon low tech, low light tank and it is doing well (4-5 months in that tank)

Since i have a 55G, I use a python. So if i were to start by adding 1/4 tsp per water change (25 gallons), could i gradually add it directly to the tank? Like sprinkle a bit in gradually as the water is refilling? Using buckets while doing 25G water changes would be too much of a PITA, not to mention i dont think I enough muscular enduarance to heave those heavy buckets up there

How often do you check KH? I dont want to start adding baking soda and then my city water changes again and i come home to 25 dead fish...

TIA

 

[gu2high]

I bought a bag (15lb?) of Floride crusched coral for $15.99 at Petsmart store. It will last life-time if you just use it to condition pH.

 

[7Enigma]

Basically all GH is important for is to make sure you are not deficient in the macro nutrients Ca and Mg.

Does this explain why snails never did well in this tank (never last over 1 month)? I have an apple snail in my 10 Gallon low tech, low light tank and it is doing well (4-5 months in that tank)

Since i have a 55G, I use a python. So if i were to start by adding 1/4 tsp per water change (25 gallons), could i gradually add it directly to the tank? Like sprinkle a bit in gradually as the water is refilling? Using buckets while doing 25G water changes would be too much of a PITA, not to mention i dont think I enough muscular enduarance to heave those heavy buckets up there

How often do you check KH? I dont want to start adding baking soda and then my city water changes again and i come home to 25 dead fish...

TIA

It's definitely a possibility but not the first thing I would suspect (though the apple snail being fine is an oddity). First thoughts are always something like copper or other heavy metals in the water but again the apple snail doesn't fit with that hypothesis. Another thought would be something specific in the tank causing the snails to die. You actually found them dead I assume correct? Not that they just dissapeared right? Some fish will nip for fun causing deaths that look to be natural...

Anyways as for the baking soda...I never check my KH....ever. I do 50% PWC's each week and so am confident my tank stays at a consistent level. With a python your best bet then would be to get a squirt bottle, say 20oz. Put the appropriate amount of baking soda into it and fill it with water (I'd use used tank water). Shake the bottle making sure it completely dissolves, and then as you are adding water back into the tank (near the python outflow) squirt the bakingsoda solution in evenly. This isn't a perfect method, but you should get good enough in 1 or 2 tries that it shouldn't cause problems.

I'm not a proponent of crushed coral.