Low pH + High KH?

[Snazzy]

Heres my tank parameters:

 

10gal display

5.5gal sump refuge (half full)

 

pH: 7.9

dKH: 11.2

Ca: 350

Mg: 1300

Dosing Strontium and Iodine Iodide and DT's every so often

SG: 1.024

 

Straight R/O for Top-Offs

 

R/O and IO for salt

 

Doing 2 WC's a week at 2gal since my pH and KH was screwed (2weeks). Ive stoped dosing everything. All my corals look healty and open up.

 

whats ideal range for a reef tank? ~8 dKH? and 8.3 pH?

 

any ideas that are causing my high KH? and any ideas to fix it besides keep on doing WC's?

 

edit:

 

i have about 15lbs LR total and about 3/4" LS

and i run purigen

[Gwoardnog]

Low pH + High KH?

sounds like a chronic case of using PH+ cure-all type solution.

 

11.2 dKH is fine (unless I have my KH abbreviations mixed up).

 

You can add calcium supplement to bring up your Cal and it also has the added effect of lowering your Alk. They're connected like that.

 

8-12 is what most shoot for on the dKH ~11 about the norm for elevated growth

~500 Calcium too, more than that is a bit too elevated.

 

PH is what it is. leave it and don't try to mess with it unless it's below 7.8. And even then don't use a PH+ solution.

[MrAnderson]

You can add calcium supplement to bring up your Cal and it also has the added effect of lowering your Alk. They're connected like that.

 

only at concentrations approaching precipitation.

 

raising the calcium like gwoardnog suggested is a good idea regardless. otherwise, i don't think any of those parameters are much of a concern.

 

pH also rises throughout the day, all tanks do this, as well as on natural reefs; it's a function of dissolved CO2 concentrations. when did you measure the pH? if the measurement was within a few hours of lights on it's probably is fine. don't try to correct pH with buffers, solve the CO2 problem instead (if it IS a problem, that is. a measurement at lights-off will tell)

[Snazzy]

so whens the best time to do a test?

[MrAnderson]

so whens the best time to do a test?

 

there isn't a single "best time". test at lights-on, and again at lights-off to determine your pH range. the pH values at those times will always be different unless your tank is completely dead.

 

photosynthesis throughout the day consumes CO2 and drives pH up so that it peaks at lights-out. respiration of animals and plants throughout the night with no photosynthesis produces CO2 and drives pH down.

[Snazzy]

there isn't a single "best time". test at lights-on, and again at lights-off to determine your pH range. the pH values at those times will be always different unless your tank is completely dead.

 

so technically i guess if i get this right the pH would be lower at lights on because of the co2 build up over night and at lights off the pH should be at its max b/c of the decreace of co2 by photsythesis etc.

[MrAnderson]

exactly (i edited as you posted)