Ph Crash in three well established tanks

**Tiari** · 02-14-2013, 12:56 AM

Three of my tanks are suffering a PH crash, the PH hits the lowest on the API test kit, and I'm guessing it might even be lower. The problem was identified by one guppy in one of the tanks hovering at the bottom in a corner, A black mystery snails shell going hazy and Oto cats refusing to eat fresh food. Immediately seeing this, action was taken (immediate water changes, testing so on) and the PH fallout was detected.

History on all three tanks: WELL maintained. Regular maintenance performed in OCD like fashion, (lol not so OCD I destroy BB), these are not neglected tanks. Every Wednesday like clockwork, gravel vacuum (every other week is a general light sweep, the other decorations are moved and all the gravel gets a good hoover), filter media rinsed in removed tank water. Prime water conditioner used, and each tank has more than one filter. Filters are as follows:

20 Gallon - AC 30, AC 20, Elite sponge air driven filter
10 Gallon - AC 20, Cylindrical tube air driven sponge filter
5 Gallon Edge - Duetto 50, Cylindrical tube air driven sponge filter

Tank API Freshwater Test readings:

20 Gallon - Ph 6 or below (test tube color turns a weird yellow not the one on the chart, this is the same for all three tanks), Ammonia 0, Nitrite 0, Nitrate 10ppm

The nitrate on original testing when problem was noted was a skyrocket high 80PPM, it could have even been higher. This is mind boggling as the tank is pristine and well maintained. Brought down to 10ppm by water changes over three days.

10 Gallon - Ph6, Ammonia .25 (also perplexing, this tank was well established and cycled), Nitrite 0, Nitrate 5ppm

5 Gallon - Ph 6, Ammonia 0, Nitrite 0, Nitrate 0 (the nitrate at 0 baffles me as well, and am concerned cycles stalled out with low Ph)

I have done GH/KH testing, API kit, all three tanks read exactly the same:

KH (4 drops) 71.6 GH (6 drops) 107.4

All three tanks have crushed coral in the filters, quite a bit of it too, several teaspoons, and the Ph is this low. I am stymied.

Since we just had a blizzard here, I did test the water out of the tap, the PH is 7, I have not done GH/KH testing on it. It is possible however, that before this test (today) it may have been different due to the storm? This I am not certain of.

The outrageous Nitrate reading on the 20 blew me away. There is no reason for it, no detritus anywhere, filter boxes are clean, nothing dead, no rotting food, debris, nothing. The last test I did the week before just before maintenance was 20ppm. Ammonia showing up on the 10 is alarming to me, again same thing, nothing lingering anywhere, it makes no sense.

Any theories appreciated, I'm completely baffled.

**madagascariensis** · 02-14-2013, 01:00 AM

Blizzard messed up your water supply? A large volume of rainwater can drive down ph and hardness drastically, as well as increase impurities in water supply

**funkman262** · 02-14-2013, 01:17 AM

Have you tried verifying those results with a different test kit (maybe take it to a local fish store)? If not, how old is your test kit? As they age, they become less reliable.

Originally Posted by Tiari

5 Gallon - Ph 6, Ammonia 0, Nitrite 0, Nitrate 0 (the nitrate at 0 baffles me as well, and am concerned cycles stalled out with low Ph)

Doubt it. If the cycle stalled, you'd be seeing an ammonia spike. How hard/long do you shake the second bottle of the nitrate test?

**KevinVA** · 02-14-2013, 01:23 AM

That's possible. Did you have the same problem with Hurricane Sandy? =/ If not, I would cast doubt.

Why are you using crushed coral in your filter? Do you have soft water?

Have you tested your tap for the usuals, like Ammonia, Nitrite and Nitrate?

**Tiari** · 02-14-2013, 02:40 AM

Tap water has Ph 7, ammonia 0, nitrite 0, and nitrate just a hint of color change on the test.

I shake my #2 bottle for nitrate test for 60 seconds vigorously, every time! The tests are not expired, the test liquids are regularly replaced, so I doubt that's it.

The crushed coral is I've had unresolved crash issues from the start up, I do know my Ph will not hold, or not hold for long. This is a well known issue with my tanks, as well as others with tanks in my city that I know. I have a past post where I attempted to resolve the issue, and did so with crushed coral (as have the others in my city that I'm friends with).

My main concern is, the low Ph WITH the crushed coral in the filters. This I have no idea.

Yes, I had difficulties after the hurricane last fall, but that was due to power failures, not water from the tap.

**KevinVA** · 02-14-2013, 04:28 AM

I'd be curious to know if crushed coral stops releasing minerals into the water after a while. I actually use it for a substrate in my Nerite snail tank, but I also add rocks. Both had raised my pH considerably from 7.0 to 7.6. Have you thought about adding rocks to your tank? And not the "safe" ones...

**Tiari** · 02-14-2013, 01:01 PM

I was wondering that too Kevin. However I have fresh coral in the filters, and so far, the PH is not going up. If it doesn't I might look into other options at this point.

**KevinVA** · 02-14-2013, 01:52 PM

Well, if you do add mineral-enriched rocks, be sure to add them one at a time and test the pH (maybe 1-2 a day or something). I know fish are able to handle swings in pH, because water usually becomes more neutral and sometimes acidic at night, but a bigger swing due to added hardness could throw them into osmotic shock.