Epic fish loss - Low PH?

[LanaK]

Hi All,

Lost a whole tank of endler's overnight - probably close to 50 fish (lots of babies).  The 3 BN plecos in there seem fine for the moment.  Check the parameters and the the water was very hard, and the ph was super low, like off the charts low.  What causes the PH to drop like that?  Sponge filter, heavily planted tank, I had done a water change on Wednesday and squeezed out the filters into siphoned tank water, so it might have been a spike, but this tank has been established for months and months.  Tested PH of my tap water and it is in the normal range.

Thoughts?

[Regalblue]

I sent this to a friend,  his response....

There are several  possible  things for the ph crash. First  test the source. But you want to test it after letting it sit for 8 hours. This time of year due to cold nitrogen and co2 gasses build up in tap supplies. It can come out high at first but as these gases evaporate  from the water the ph can crash. Another  potential  issue with out knowing what the substrate is and some other factors... dissolved organics  can cause crash.  If this tank has co2 system  it will cause ph to drop. Would  need to know the KH. One can have high GH but low KH. Water general  hardness  is high but the ability to hold ph is poor due to a lower kh value.  Either  decaying or high dissolved  organics  can effect it if the kh drops. And a co2 system.  These are just some possibilities there are others.

[LanaK]

Yeah it has gravel substrate, but a LOT of plant matter.  No Co2 system.  The KH was super low as well.  I am guessing that it was the decaying plant matter?  I let the water out of the tap set for a day and it has normal measure, hoping that the water change from this morning didn't hurt the remaining fish. 

[LanaK]

Ok, lost that tank again. Same issue.

Tested the tap water, after 2 days in the room aerating, out of tap, like 8, Day 2, 7.5, Day 3, down below 6.  I know that city water uses buffers, but can it really be that much?  And if so, what do I do to combat it?  RO water system?

[LanaK]

I did find this article about Ann Arbor's water treatment process... Apparently they lower the PH to treat it, then buffer it when sending it into the homes....Could my problem be that the buffer wears out after a few days?


Ozonation Optimization. AAWTS operates an ozone disinfection system as a primary
disinfection treatment process. The high energy costs of producing ozone led AAWTS to
investigate whether manipulating the water conditions would result in water that is easier to
treat with ozone and thereby uses less energy for the ozonation process. Prior to any
full-scale construction, AAWTS conducted a pilot study to see if changing the water
chemistry could result in lowering the energy demand for operating the ozone system. The
pilot study results showed that depressing the pH of the water with carbon dioxide before
ozone application and then raising the pH with caustic soda after ozone treatment improved
the efficiency of the ozonation process and reduced its energy needs.
Operating the ozonation disinfection system under the depressed water pH conditions has
reduced the ozone generation energy costs. It is difficult for AAWTS to quantify the savings
since the ozone process has only been operated with the depressed pH process since the
pilot study was done prior to the completion of the ozone plant. The energy savings costs
from less ozone generation must be balanced against the added costs of the chemicals used
to depress and then raise again the pH, as well as the chemical pumping costs.

[LanaK]

Other signs that something is wrong/is about to go wrong is the duckweed starts dying/bleeching out and so does my Madagascar lace.  Could it be something besides low PH that just happens to cause it as well?

[Malawifish]

I had a tank go down the same way I used a poly filter to find out what the water was doing (poly filter will change colors to give you an indication on what is going on), it was plant mater decaying. lost almost every fish...good luck😀

[LanaK]

Those Poly filters sound amazing.... will have to investigate those for the other tanks before something else dire happens

[Marty]

If you can't put crushed coral in your tank, perhaps you could get a food grade barrel and put a large bag's worth (approx 40lbs) in the barrel and store water in there.

[mightieskeeper]

Marty has the best idea to fix your problem.  If you use buffers you have test religiously to prevent a sudden change.

[LanaK]

So if I was to add crushed coral to some of the tanks, is there a rule of thumb as to how much to add per gallon to act as a buffer?

[Malawifish]

I'm not 100% on this but I think you could use crushed coral in a calcium reactor for the same effect, but will need to change it out periodically probably very 3 or 4 months. I'll do some more research on it. Basicly a calcium reactor is a container filled with medium to add the necessary calcium back into a tank (crushed coral is calcium). Your return hose goes into one side that moves water over the medium, and it has another outlet to the tank that you use as the return. But the way I see it, it should work as a buffer as well.

[Malawifish]

That is NOT the direction you want to go, it's way to complicated for a fresh water system.

[LanaK]

If it helps, most likely I will be getting two 55 gallon drums this week to store the water in before it goes into the tanks and I was thinking that would be the place to get the PH back up.