rnbo Posted May 29, 2007 Report Share Posted May 29, 2007 I have a 120L tropical. Has been set up for a long time and this week noticed that the fish were looking stressed and the pH was reading 6! Did a water change and had to adjust pH back to 7ish. A couple of days later pH was again 6. Again adjusted. Other water params fine. Any thoughts on what's happening here?? Quote Link to comment Share on other sites More sharing options...
Caryl Posted May 29, 2007 Report Share Posted May 29, 2007 The fish will be even more stressed with the pH swings you are creating. I have heard of pH crashes but can't remember what causes them. :roll: What else is in the tank? I had a tank of cichlids and the pH always dropped to 6 - 6.5 whereas the community tank stayed at 7.0. Quote Link to comment Share on other sites More sharing options...
davidb Posted May 29, 2007 Report Share Posted May 29, 2007 pH crashes are caused by a low kH Caryl. What is in the tank RNBO? What fish, plants, driftwood rocks, substrate, what filtration are you using and are you using CO2- answer those questions and we may be able to help out! Quote Link to comment Share on other sites More sharing options...
rnbo Posted May 29, 2007 Author Report Share Posted May 29, 2007 Eheim 2213, 2 angels, 10 cherry barbs, 2 yo yo loaches, 4 bn. Planted tank w substrate for plants gravel overtop, 3 small driftwoods and couple small caves. No CO2, small amount of air. If it was a kH problem why haven't i had it before.... Auckland water quality is pretty much the same isn't it? Also the same in other 3 tanks... Yoyo's are a pretty reliable sign of stress as their colours go really pale... afta pH adjusted colour comes back pretty quickly and fish look much happier haven't noticed any problems with fish afta adjusting pH shift...they settle right on down and stop stress behaviour. Only difference that I can think of have feed Nova tabs instead of shrimp pellets.... Quote Link to comment Share on other sites More sharing options...
herefishiefishie Posted May 29, 2007 Report Share Posted May 29, 2007 Get your tap water tested for hardness first. Gh & kh. Your local lfs should be able to help you. Is the driftwood leaching much, as in is the water a tinge of brown? Frenchy Quote Link to comment Share on other sites More sharing options...
rnbo Posted May 29, 2007 Author Report Share Posted May 29, 2007 No The water is not brown tinged...woods have been in the tank as long as I have had it...3yrs I guess th bn's will expose new wood all the time but don't think this is it! Does anyone know what Auckland's water is like?? Quote Link to comment Share on other sites More sharing options...
Ktttk Posted May 29, 2007 Report Share Posted May 29, 2007 Auckland water. I got this report after I emailed metrowater in July last year asking about the water supply in Auckland. Highlighted in the orange box is the measurement of hardness. The units on the right hand column of mg/L is equivalent to ppm (parts per million). MAV is Maximum Acceptable Value set by the Drinking Water Standards for New Zealand 2000 (DWSNZ 2005), given for determinands with a health significance. GV is Guidline Value set by the DWSNZ 2000. Established for aesthetic determinands. ** = Conductivity is an indirect measure of the TDS in a water supply. TDS = Conductivity x (an empirical factor which ranges from 5.5 - 7).The conductivities of New Zealand water supplies range up to 100mS/m but are typically less than 30mS/m. And to interpret this value, I have found a table at this site, which also gives a good basic explanation of what pH, kH and gH are. So a hardness reading of 29.2 ppm from the table is equivalent to about a dH of about 2 (0 to 4) which indicates that the Auckland water supply is very soft - hence not much pH buffering capacity. A simple way to increase the hardness in order to improve the pH buffering capacity is by adding things like marble chips or oyster shells which contain CaCO3. Hope that helps. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 30, 2007 Report Share Posted May 30, 2007 The hardness of the water has nothing to do with pH buffering. The carbonate reacts with the hydrogen ions to increse the pH and since it is there usually as calcium carbonate it leaves calcium behind which increases the hardness. Quote Link to comment Share on other sites More sharing options...
David R Posted May 30, 2007 Report Share Posted May 30, 2007 Is the driftwood leaching much, as in is the water a tinge of brown? I've got some big pieces of wood, but they're all quite old and there was no sign of leaching. I checked my pH [after ignoring it for months] and it was bright yellow, off the chart!! I didn't bother trying to adjust it, it goes up to somewhere around 6-ish when I do a water change, and I've added a few big bits of coral to the sump which has seemed to stop it dropping so low. Quote Link to comment Share on other sites More sharing options...
Ktttk Posted May 30, 2007 Report Share Posted May 30, 2007 The hardness of the water has nothing to do with pH buffering. The carbonate reacts with the hydrogen ions to increse the pH and since it is there usually as calcium carbonate it leaves calcium behind which increases the hardness. That is true alan. Hardness is a measure of the concentration of dissolved metals in the water (such as Ca, Mg, Zn) and does not directly affect the pH. It is the concentration of carbonates and bicarbonates, which is also referred to as the alkalinity or temporary hardness that acts to buffer the pH. But because the dissolved metals are generally found to be bound to carbonates and bicarbonates, a high hardness measurement is normally associated with a high kH and hence hard water is usually well buffered. But there of course there are situations where the water maybe hard (high Ca, Mg etc) but there are low levels of carbonates and bicarbonates in which case you will get hard water that is poorly buffered. Quote Link to comment Share on other sites More sharing options...
sharn Posted May 31, 2007 Report Share Posted May 31, 2007 I add shell grit (stuff birds eat) in stockings to my filters. works a charm at upping my kh (0 out of tap) which in turn raises my ph it a bit. Quote Link to comment Share on other sites More sharing options...
rnbo Posted May 31, 2007 Author Report Share Posted May 31, 2007 Sounds like I need to get me some grit!! :lol: Thx for the help Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 31, 2007 Report Share Posted May 31, 2007 The point I was trying to make was that you should be aware that adding calcium carbonate in any form to raise the pH will aso increase the hardness. If you don't want increased hardness you will need to get rid of it with water changes and water changes will also increase the pH as tap water is normally slightly alkaline---so why worry about the grit. Quote Link to comment Share on other sites More sharing options...
rnbo Posted May 31, 2007 Author Report Share Posted May 31, 2007 Bird grit is usually ground up shell... Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 31, 2007 Report Share Posted May 31, 2007 Shell is calcium carbonate Quote Link to comment Share on other sites More sharing options...
Ktttk Posted May 31, 2007 Report Share Posted May 31, 2007 I think that drops in pH, as rnbo is experiencing is more detrimental to the health of the fish than a small increase in hardness. Adding shells/bird grit to the tank in gradual amounts will help to stabilise the pH over time. Quote Link to comment Share on other sites More sharing options...
rnbo Posted June 1, 2007 Author Report Share Posted June 1, 2007 duh....referring to shell being calcium carbonate...don't get your point alanmin...surely I need to increase hardness with the very soft auckland water I've got which has no buffering capacity. If I don't do it with shell then have to add expensive salts from lfs Quote Link to comment Share on other sites More sharing options...
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