calcium reactor and dkh levels

[elliottargyle]

I have a calcium reactor set up right now that's been running for about 5 weeks. All parameters are good, but I can't get my dkh to stabilize. I've adjusted my drip rate and bubble count numerous times and waited patiently....still can't get the thing dialed in. My tank is ran at 78 F, ph is 8.3, calcium - 420 and holding steady, magnesium is 1350, salt is at 1.021. Phosphates, nitrates iets, ammonia are always at 0 or acceptable levels. I'm using course korallith media and I'm down to about 6.4 ph in the reactor chamber. I've read that it usually takes a lower ph to dissolve this stuff when compared to the ARM. I'm at about 5 bubbles per min, and about 120 drips per min of effluent. My tank is about 125 gallons total with only 2 small fist and about 150 lbs of live rock. not that many corals really. I've been having to supplement superbuffer because of the continuing dropping dKH. My tank is using about .6-1.0 dKH per day. Could I be having a hard time keeping my dKH up because of my salinity(1.021 or 27.9 ppt)? Should I slowly increase this to 35ppt? or what else can I adjust? Everything is doing great, but I'm getting frustrated trying to adjust my reactor.

Please help.

[tkeracer619]

You want to ignore calcium at first. Adjust the reactor until you get a stable dkh. Then adjust calcium as required via dosing.

You can probably drop the ph down in the reactor without problems or increase effluent flow and bubble count to keep your same ph but with more flow through the reactor.

[RokleM]

Any reason you want such a low salinity? Your parameters will be a bit high after you get it to the correct salinity. Your tank shouldn't be using 1 dKh a day with little to no corals (unless you have a massive amount of coralline). You never listed where you dKh is.

Once you get the salinity stabilized, here's a calculator to help you fine tune the setup.
http://reef.diesyst.com/reactor/reactor.html

[elliottargyle]

I think the main reason why I chose that salinity is because that is what our local fish store runs theirs at. I guess I've never really thought about changing it...but now I think I will....very, very slowly of course.
My original dKH when I first installed the reactor was around 9. I do have a TON of corraline growing everywhere. The back of my tank is a giant sheet of the stuff and my rocks are completely covered as well.....I basically have to scrape the front of my tank about every other day.

Should I start with raising my salinity? and with that should I adjust my temp (78 F)?
My tank evaporates around 1 to 1.5 gallons a day....I live in South Dakota and it's cold and dry right now....the temp outside is currently at -16 F! With raising the salinity...should I shut off my RO/DI topoff?...or would that be to much of an increase? Tank volume is around 125 total... 46 gal bowfront, 2 x 40 gallon sumps (one is filled with live rock, and the other is just for volume), and a 25 gallon ref. I'm overkill for only having a 46 bowfront but I wanted to build up the important stuff first and then upgraded to a 120-200 gallon tank.

[RokleM]

That's a relatively large salt cost savings a year. Not uncommon for LFS.

I would slowly raise it yes. You can either topoff with saltwater or a RO/DI and saltwater mix for a while to let the parameters slowly even out.

[elliottargyle]

Thanks again.....we'll see how everything works out!