Water change- Induce spawning problems

[AndyAps.com]

Hello, i am having problems getting my zebra's to spawn (as anyone who remembers me will know lol).
Basically i am trying the let it go a bit then do a water change to fetch conditions back to perfect (i.e dry season rainy season method)
However i have let the tank go over the past 2 month's, fed plenty high temp etc. the parameters today measure GH 260 (very high) however KH is less than 10, this doesnt suprise me as my tapwater is very soft to start with and has very little carbonate hardnes however the general hardness will have risen due to fish waste building up etc. the nitrates also measure highly (50)...i know this sounds high but im watchin closely and all are ok Nitrite is 0 by the way. Ph is 6
OK so today i figure i will do a large water change with a lower temp and lower GH KH and a similar PH.............However, i measured the tapwater that i stored overnight and the GH and KH are fine (90 and 20 respectivley) however the PH is 7..........
How can i do a 50% water change with that, the PH is at least going to even out at 6.5 which is effectivley 5 times more alkali and will shock the fish................my question is how can i lower the PH to suit? or will this be fine and im worrying over nothing?
The action i have taken at the mo is to take out 50% and only add back 25% at PH 7 and then maybe add the other 25% 2morrow when its evened out again.
i'd love a bit of help from the older more professional members if possible>............Rob? Plastic mac? ceasers? jerms? barbie?mceve?

[AndyAps.com]

Come on surely someone must have a comment on this?
HELP PLEASE

[Barbie]

The odds are good the pH won't come back up to 6.5. It may come as high as 7, depending on the buffering capacity of the tap water, or it may continue to stay low. If you're using a chemical drop test kit you need to get the pH up in the zebra tank anyway, as they don't show when the pH goes below 6 and I speak from experience, zebras won't fare well in lower pH conditions. The rise in pH from a water change won't stress them badly as long as it stays acid to neutral, and it should with your conditions. If you're really worried, do a 20% change for 2 days, then start going with larger volume changes. I'm not sure your TDS got high enough to really give you the sway in parameters that you need, but you'll know in a few weeks, either way .

Barbie

[AndyAps.com]

thanks for the reply barbie.......looks like im not too popular lol.
My PH test kit goes as low as 5 and is brand new so is accurate. as regards the GH/KH why do you not think i let it go high enough? what sort of reading do you think i shoudl experiance before i drop it again to get the required parameter sway? i thought 260 down to under 100 would be big enough??????
Thanks

[Barbie]

260 down to under 100 ppm wasn't enough for mine. It had to get over 300 before I did the rains, but once my fish were spawning, even a minor change would set them spawning. You'll know in a week or two if it worked this time and if not you know to let it get a bit harder first. No worries .

Barbie

[Mindy]

My pH also drops very low. My test only goes down to 6 and it matches that. I have no idea if it's lower, but the fish are fine. I do maybe a 15% water change with remineralised water and the pH never goes higher. I'm not really sure what to do....