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View Full Version : Need help with low pH in a 225g


jabel
10/10/2009, 02:25 AM
I've been stuggling for the last few months trying to keep my system pH above 7.8. Each time it goes below the tips on several of my sps burn. The rest don't seem to grow much. I've read just about every article available and talked to many friends with well behaved tanks and I just can't figure out how to fix this. My pH ranges from 7.8 to about 8.1 during 24 hrs. My alk ranges between 9 and 11, my ca is around 400 and my mg is 1350. I've tested these continuously over the last few months. Here's my set up. I use a small GEO ca reactor with a 2nd chamber and depending on what I'm doing, it seems to be able to maintain my alk. I run calk in my top off and I have that scheduled to run during my low pH period. I use three 400w MH lights that run about 8 hrs each from 4pm till 1am. I have a refugium that runs a small home depot light on an opposite time to the tank and a small frag section in my sump with a 250w MH that runs from about 3am till 10am. My low pH comes between 10 am and 4pm. I also run a bubble master 250 skimmer.
I've replace my pH probe and double checked it with a 3rd meter. I tried agitating the water surface as much as possible to get better co2 exchange and my ca reactor efluent exits near my skimmer intake. I usually leave my windows open each night so my house should have a good air exchange with the outside as well.
Any thoughts? I'm out of ideas and getting more and more frustrated.

Thanks,
Jeff

HighlandReefer
10/10/2009, 05:42 AM
I am not sure if the burnt tips are due to the low pH of 7.8 that you have occurring. In natural reefs, the pH can change from 7.8 in many cases and swing up to the high end of the scale (8.5) with no appearant negative effects. In addition there have been several Tanks of the Month, that have pH low levels below 7.8 with no appearant problems.

I would max out the use of kalk water and then supplement the remaining tank needs with a high pH alk supplement like "baked" baking soda if your concerned about your pH. ;)