9.9 ph.....what to do

[Laurie Roberts]

I have 2 -500 gal tanks with gravel bed system.  My well water tests 7.6 ph.  We started a fishless cycling per Murray's site just using maxigrow and will add fish in a couple weeks if all goes well.  We put in some small plants just to start so by the time fish come in, they will be more established.  I have tested twice in last week and everything is 0 which is to be expected but the ph is reading 9.9.  I ready that to get it down, I could use lemon juice so I just added that.......now I am thinking it was a mistake after reading some other sites.....it could hurt the bacteria .  Should I empty my tanks and start over ?  Also, my gravel must be adding to the ph......what can I do long and short term to address this ?  I dont care about the plants at this point.....just the health of systme down the road.....thanks for any input 

[George]

You could try fishless cycling as described on this site Start Here/Rules of Thumb to see if nitrification brings the PH down.  If it doesn't, then change the media to something with neutral PH.  You really need to be cycled before adding fish and that is a 6 week or longer process.

Did you try a fizz test on the gravel?  If no, try some vinegar on the gravel to see if it fizzes.  You can search this site for more information on the subject. Do this first.  If you have high PH gravel then you may as well swap it before cycling.

Lemon juice should not be used to lower PH.  There is a PH down product for aquaponics but it shouldn't be necessary to lower PH since cycling will lower PH.

[Laurie Roberts]

thanks George.........I did do a fizz test and it is nuetral.  I found out that my meter is probably not calibrated right.  Did test again with pool strips and it tests 7.6 and with api kit and get different reading with the high and low tests but it is right around 7.6 so I think I am good.  I added some pond water from healthy system and am definitely waiting to add fish.  Hopefully the lemon juice I added that one time wont be a problem.
George said:

You could try fishless cycling as described on this site Start Here/Rules of Thumb to see if nitrification brings the PH down.  If it doesn't, then change the media to something with neutral PH.  You really need to be cycled before adding fish and that is a 6 week or longer process.

Did you try a fizz test on the gravel?  If no, try some vinegar on the gravel to see if it fizzes.  You can search this site for more information on the subject. Do this first.  If you have high PH gravel then you may as well swap it before cycling.

Lemon juice should not be used to lower PH.  There is a PH down product for aquaponics but it shouldn't be necessary to lower PH since cycling will lower PH.

[George]

I use API and generally PH is the only test I do.  Since my first partial cycling and killing the first batch of fish, my system has never had high ammonia or nitrite.  Something you need to be aware of is too low PH can kill your bio filter.  After adding fish, the more you feed, the faster your PH will fall.

good luck to you

[Alex Veidel]

Although, if she's using well water, then her kH might be high as well. Then it would take significantly longer for nitrifying bacteria to produce enough acid to bring that down.

Laurie, if it doesn't start lowering by itself in a couple weeks, then I would consider getting an API KH test and see what your carbonate hardness is at (carbonate hardness can act like a pH buffer, so if your carbonates are high, then your water will be stuck at 7.6 until the acid produced by nitrification uses up all the carbonates. Well water can have a pretty high KH sometimes, and you don't want your water stuck at 7.6 for too long.)