what causes the PH crash?
- Thread starter bamdad
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I don't believe your PH can crash so to speak. If it rapidly drops over a short period of time, im thinking one of two things happend: 1) you chemically altered your water either with store bought chemicals, driftwood, peat, etc., 2) you did a massive water change with water of a ph much less than your original water.
I'm assuming most of the PH problems here are caused by bad water quality. Most new fishkeepers don't realize how crucial frequent water changes are. If you go too long without water changes, your water quality deteriorates, your alkalinity drops which in turn allows your PH to steadily drop. In low PH, ammonia becomes much more toxic. Then when they finally do do a (most likely large) water change, theres a drastic swing in the water chemistry.
I'm assuming most of the PH problems here are caused by bad water quality. Most new fishkeepers don't realize how crucial frequent water changes are. If you go too long without water changes, your water quality deteriorates, your alkalinity drops which in turn allows your PH to steadily drop. In low PH, ammonia becomes much more toxic. Then when they finally do do a (most likely large) water change, theres a drastic swing in the water chemistry.
hummm thats right mate, i thought of this too but then i worried that there might be sth or a common mistake that could change your PH dramatically... tnx by the way :headbang2:
Actually, those of us with very soft water can have a ph crash because our water has no buffering capability. My water comes out of the tap with a ph of a little over 6 as it is, so my main concern is to avoid anything that might lower the ph because not only will it lower it dramatically, it will do it very quickly. I onlt felt comfortable adding driftwood to my tank after boiling it every day for a week and then soaking it for another week to be certain all the tannins were leeched.
Most folks here have hard water so you have different concerns. Of course, it would be easy enough to add crushed coral or cuttlebone (as has been recommended here) to increase the hardness of my water, but that would also increase my ph and I keep fish that thrive in the lower ph range.
I add no chemicals to my water except water conditioner, I do frequent water changes, and I clean my canister filter (with tank water) every other week.
Most folks here have hard water so you have different concerns. Of course, it would be easy enough to add crushed coral or cuttlebone (as has been recommended here) to increase the hardness of my water, but that would also increase my ph and I keep fish that thrive in the lower ph range.
I add no chemicals to my water except water conditioner, I do frequent water changes, and I clean my canister filter (with tank water) every other week.
I agree with the above^
It basically comes down to a low Kh. If anything is added to raise the pH and the water cannot support the change, it "crashes"
It basically comes down to a low Kh. If anything is added to raise the pH and the water cannot support the change, it "crashes"
explain please.
kH is directly related to pH. a high kH tends to support a more stable pH.
sometimes pH is changed by acids in the water.or.some of the calcium on the kH may get consumed over time which lowers the kH value and this in turn provides a less stable pH. or calcium may precipitate out of the water etc.
those of us with a low kH minehovers btw 3-4 DK watch out pH and kH.
I have not seen a pH swing inmy tanks as a result of low kH CO2 in my tanks will lower pH but the kH is unaffected.
a tank that is not maintained well may suffer pH swings as hydrogen ions , acidify the water, they bind up the buffers..when there are no more buffers the tank will see a drastic swing in pH. (lower.)
carbonates added to a low kH tank or acidic tank usually dissolves and adds calcium carbonates which in turn will help to raise the pH..the in some cases it doesn't work.
kH is directly related to pH. a high kH tends to support a more stable pH.
sometimes pH is changed by acids in the water.or.some of the calcium on the kH may get consumed over time which lowers the kH value and this in turn provides a less stable pH. or calcium may precipitate out of the water etc.
those of us with a low kH minehovers btw 3-4 DK watch out pH and kH.
I have not seen a pH swing inmy tanks as a result of low kH CO2 in my tanks will lower pH but the kH is unaffected.
a tank that is not maintained well may suffer pH swings as hydrogen ions , acidify the water, they bind up the buffers..when there are no more buffers the tank will see a drastic swing in pH. (lower.)
carbonates added to a low kH tank or acidic tank usually dissolves and adds calcium carbonates which in turn will help to raise the pH..the in some cases it doesn't work.
For more, google pH and buffer capacity
in short, any salt that has any effect on pH also has some buffering capacity -having more buffering capacity inyour tank than in the little bit (or 50% or whatever) of repalcement water is what keeps the replacement water from dictating your tank's pH
"Crashes" happen when your tank's buffering capacity is low enough that any little glitch in tapwater pH used in a water change, anaerobic gas pocket burp or case of fishy-trots throws your pH off a whole lot.
The surest way to induce a crash is to use RO/DI replacement water w/o any gh booster for a lengthy series of small PWCs. Once the gh gets too low, some tannin spewing driftwood or dead fish can move your pH >2 units in <1 hour and you have problems (compounded by osmotic stress)...
in short, any salt that has any effect on pH also has some buffering capacity -having more buffering capacity inyour tank than in the little bit (or 50% or whatever) of repalcement water is what keeps the replacement water from dictating your tank's pH
"Crashes" happen when your tank's buffering capacity is low enough that any little glitch in tapwater pH used in a water change, anaerobic gas pocket burp or case of fishy-trots throws your pH off a whole lot.
The surest way to induce a crash is to use RO/DI replacement water w/o any gh booster for a lengthy series of small PWCs. Once the gh gets too low, some tannin spewing driftwood or dead fish can move your pH >2 units in <1 hour and you have problems (compounded by osmotic stress)...
Erg, sorry I was getting a bit ahead of myself. Ammonia is indeed more toxic in more alkaline water, water with 7.4+ PH. As the PH starts to drop below 7, ammonia begins to convert to a less toxic ammonium. Biological filtration starts to begin to fail once the PH drops below 6.4 which causes ammonium build up. This is ok for the time being because it in a less toxic form, however, this is very dangerous because a sudden upward shift in PH from a long overdue water change will convert the high levels of ammonium into high levels of ammonia.
Also thanks for bringing up that fact SanguineApple. Though it is not too common, there are plenty of people who have low ph tap water. IMO best defense is to test your tap water straight out of the faucet and plan accordingly and take necessary precautions.
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