PH drops even with tds of 200

[engiskhan]

I use an r/o unit since my city uses chloramine.

I use r/o right until my tds meter shows about 200 tds and out of the barrel (water is aged more than 24 hours) PH is 7.2, however, after checking my tank maybe 10 hours after water changes, PH is at most 6.0.

I change about 75% of the water daily and I do not overfeed. what could be causing this and how can I correct it?

[boxlotfish]

Hi: I would suggest that you are probably using Amquel in the city water or at least the water is heading in the right direction for Discus.

[engiskhan]

Hi,

I am using amquel as a prophilylactic but my concern is that the PH drops 2 points after I add in 35 gallons of aged r/o water reconstituted with amquel, r/o right and discus essentials.

[April]

amquel will crash alkaline unstable water. id use somethin like prime instead..or..use crushed oyster shells in your filter in a nylon to keep it buffered. if your filters are full..that also could make your ph start to dive.
i keep two at least in the tank..and alternate rinsing them .

[Carol_Roberts]

Tds measures all disolved solids including salt which does not increase (or stabilize) KH or GH

[Cosmo]

Carol hit it right on the head. TDS reads what it says, total disolved solids. Doesn't really indicate much about alkalinity though with a ph of 7.2 you'd think it couldn't be too bad. I had similar problems till I started using PH Stable by Kent. It adds to your TDS though so you have to factor that in to the equation. If you read the label on RO Right, it'll tell you to use something for alkalinity after using the ro right. My water goes into the tank at about 136ppm on my TDS meter and I never have a crashing problem anymore.
hth
Jim

[Cosmo]

PS. I use the minimum on the RO Right label, i.e. 1 tsp per 10 gal if powder, 1 tsp per 5 gal if liquid, then add about 1/2 rounded tsp of PH Stable for roughly each 34 40 gal of RO I make. This consistently brings me to about 133 to 139 ppm TDS.
Jim

[drew22to375]

When I used RO right a while back it would only increase the GH. You need something else to to buffer the KH.