Water change issue.

[jamesbuf]

So I just did a 30gal water change. I get back to my computer and notice my pH has dropped to 7.3!!!! It was only 7.55-7.6 in the first place (been battling low pH the past month or so). I have a heater and maxijet mod in the 40gal brute trashcan I use for water changes. The MJ mod kicks out ~2000gph, so the water was far from stagnant. Why in the world would have the pH of the waterchange water have been so low?? Should I leave the top off the trashcan a few hours before I make the water change?? Does anyone else have to do this?? This low pH thing is really starting to suck.

[jhn]

James, When I did my water changes it would drop my ph at most .02 or .03 if at all, using IO salt. Always kept the lid on the trashcan in the back room as well with a powerhead and heater. Bad batch of salt? Is the alk low in the freshly made water?

 

I battled low ph issues due to CO2(tank in the basement) until I started adding kalk all the time with the auto-top off. Otherwise my ph overnight would get down into the low 7's.

[wreck]

do you test the PH, salinity, and ALK of the new water before you add it to your tank? That always a good idea. Also test your ALK, calcium, and magnesium levels in your tank. I had low Ph before I tested for magnesium, mag levels will drop with use of Kalk. Do you use Kalk or a calcium reactor?

Wreck

 

So I just did a 30gal water change. I get back to my computer and notice my pH has dropped to 7.3!!!! It was only 7.55-7.6 in the first place (been battling low pH the past month or so). I have a heater and maxijet mod in the 40gal brute trashcan I use for water changes. The MJ mod kicks out ~2000gph, so the water was far from stagnant. Why in the world would have the pH of the waterchange water have been so low?? Should I leave the top off the trashcan a few hours before I make the water change?? Does anyone else have to do this?? This low pH thing is really starting to suck.

[onux20]

So I just did a 30gal water change. I get back to my computer and notice my pH has dropped to 7.3!!!! It was only 7.55-7.6 in the first place (been battling low pH the past month or so). I have a heater and maxijet mod in the 40gal brute trashcan I use for water changes. The MJ mod kicks out ~2000gph, so the water was far from stagnant. Why in the world would have the pH of the waterchange water have been so low?? Should I leave the top off the trashcan a few hours before I make the water change?? Does anyone else have to do this?? This low pH thing is really starting to suck.

I have had the same problem. Water changes drop my ph. I think low point yesterday was 7.6. I added another powerhead last week to increase flow and agitation, but no positive results have been noted.

 

I know it has been hot lately, but do you have any windows open? Fresh air helps keep my Ph up by keeping CO2 levels in the basement low.

 

That

[GaryL]

this post reminded me to check my probe.....my ph always remains high, but i have alot of algae and alot of sand....but i think i will calibrate my probe this weekend just to be sure.

[jamesbuf]

do you test the PH, salinity, and ALK of the new water before you add it to your tank? That always a good idea. Also test your ALK, calcium, and magnesium levels in your tank. I had low Ph before I tested for magnesium, mag levels will drop with use of Kalk. Do you use Kalk or a calcium reactor?

Wreck

 

 

I use a Kalk reactor. I had an incident that pushed too much kalk in the tank, and my Ca went to about 550 and Alk to about 14dKh. Its been slowly lowering and what 480 and 11.2. My Mag was 1300 when tested about a week ago.

 

I don't think its a CO2 problem because nothing really happens to the pH when I open the door about 5 feet from the tank. I've left the door open for a couple hours and it raise the pH maybe .01-.02 points.

 

I've freaking stumped. I made a new batch of fresh saltwater today. I guess I'll test the pH and parameters of this batch. This getting old :(

[ctenophore]

When did you calibrate the probe last? You pretty much can't have carbonate alkalinity above 10 DKH and have pH below 7.9.

[jamesbuf]

When did you calibrate the probe last? You pretty much can't have carbonate alkalinity above 10 DKH and have pH below 7.9.

 

I calibrated the lab grade (about 6 months old) and it read the same. I even hooked up my spare pH probe and it reads withing .01-.02 of the 6 month old one. I thought the same. How can I have high Alk and low pH??

[ctenophore]

I'd post this on RC's chemistry forum. I can't keep carbonate chemistry in my head for more than a few weeks before forgetting everything.

[flowerseller]

I'd suggest you have someone else test the water and compare.

Increase circulation both above and below the rim of the tank and this is better if you at least have a window slightly open in the room.

 

If you are using both FRESH kalk and also a Ca reactor, you may not have the reactor set correctly or not enough media in it for the flow thru rate.

[Highland Reefer]

Try opening all your windows for about 4 hours and see what happens. Add a fan to the room to pull the air in.

Edited July 3, 2008 by Highland Reefer