Alk is very high

[RonD]

Should I been freaking out here about my alk level.. recently put calcium reactor in to my system.. ph in the reactor 6.6, effluent is 7.0

tank parameters are
Calcium 410
Alk 16
mag 1300
phos.. little if any 0
nitrate 25
ammonia.. little if any
ph 8.3
SG 1.24

I tested the alk with my salifert kit and then a api kit as well.. both showed 16

the SPS I have look happy as can be but the coraline is bleaching a little bit by the looks of it .. this has me worried. any ideas please and thank you

[Geodriller]

If your alk is testing at 16dKH then yes you definatly have a problem or will very soon. Stop the effluent drip asap. Your water is close to full saturation (can only hold so much ca/alk) and it sounds like you are on the verge of a "white out" mass precipitation of ca/alk. Stop adding everything but top off until you dKH is down to atleast 13. New research says SPS corals prefer a dKH of 9. Your nitrates seem quite high aswell. Now sounds like the time do do a couple spaced out water changes. In a tank with corals you should shoot for 0ppm-5ppm nitrate. Also your ammonia should be at ZERO not a little, How much LR do you have?

[Flipper62]

<a href=showthread.php?s=&postid=14242445#post14242445 target=_blank>Originally posted</a> by RonD

I tested the alk with my salifert kit and then a api kit as well.. both showed 16



What Salifert kit are you using..... Are you reading the Alkalinity in meg/L.....if so the reading should be around 2.97...3.09

[Randy Holmes-Farley]

Assuming it is accurate, I agree that you need to greatly reduce the CO2 addition rate. Either raise the pH in the reactor, or better yet, do not use pH to control it, just manually adjust the CO2 addition rate to get the tank alkalinity that you want to match the demand. :)

[RonD]

I was of the understanding that the ph level inside the main reactor chamber had to be 6.5 to 6.7 to do anything at all.. am I wrong ? thanks for the help

[Randy Holmes-Farley]

One of the reasons that I recommend against using pH to control such things is that pH is subject to substantial pH measurement errors. It may actually be lower than you think, or your media may be dissolving at a higher pH than others find (it does vary by the media), or you may just have less demand than you think. :)

[BigJay]

I had the exact same problem this weekend, 16dkh and 540 calcium. I didn't reduce my two part additions to account for the new limewater topoff. It hasn't been a problem before, but lately I'm evaporating a lot more than usual with the really dry air, at least 2-3 gallons per day.

I let the tank sit for 2-3 days without supplement, and it worked itself out. I'm back down to 11-12 alk, that's about where reef crystals is right out of the bucket. No ill effects on anything that I can see so far.

[einsteins]

<a href=showthread.php?s=&postid=14242780#post14242780 target=_blank>Originally posted</a> by Geodriller
New research says SPS corals prefer a dKH of 9.

NSW is around 7 to 7.5 DKH. I think a better way to say this would be that its shown that SPS can do well in alk as high as 9dkh.
IMO NSW levels are best.

eins

[RonD]

thanks everyone for the help.. and I am sure this has been said a thousand times already but it sure is nice to see you back on here Randy.

[Randy Holmes-Farley]

Thanks. ;)

Happy reefing!

[Genetics]

RonD, how fast do you have your effluent drip coming out of your reactor?

[MCsaxmaster]

<a href=showthread.php?s=&postid=14244992#post14244992 target=_blank>Originally posted</a> by einsteins
NSW is around 7 to 7.5 DKH. I think a better way to say this would be that its shown that SPS can do well in alk as high as 9dkh.
IMO NSW levels are best.

eins

NSW alkalinity is ~ 6.5-6.6 dKH @ 35 ppt. Variation in salinity causes variation in alkalinity as well, but alkalinity is rarely outside the range of ~6.1-6.9 dKH in the water overlying reefs.

I'm not sure the claim that "sps corals prefer a dKH of 9" makes sense for several reasons.

1) How do we assess what they "prefer" and what they do not "prefer"? What is the metric?

2) The designation "sps" coral is completely arbitrary. There's no reason to expect that corals with polyps of roughly similar size are more similar than those with differently sized polyps. That's a bit like grouping songbirds, bats, and butterflies because they all fly, and differentiating them from penguins, dolphins, and shrimp because they swim. It makes no sense.

3) What happens at 9 dKH? What evidence is there that any sort of optimum exists there?

Of the (relatively limited) evidence available, some species of coral have been measured to DIC-saturated calcification as low as ~12-13 dKH while others showed no indication of saturation at 20 dKH, all in otherwise normal conditions. It seems to take quite a lot of DIC to saturate calcification in most corals, and it varies quite a bit among species.

As for NSW alkalinity (7.0-7.5 dKH is ~10% higher than normal sea water) being preferable to higher than NSW alkalinity in captivity: why?

cj

[RonD]

<a href=showthread.php?s=&postid=14252824#post14252824 target=_blank>Originally posted</a> by Genetics
RonD, how fast do you have your effluent drip coming out of your reactor?

Quick measurment would be about 7.5 gallons per hour. I am thinking when things level out I am going to slow the CO2 down and speed up the flow. Run it this way for a bit and slowly bring them closer together in a more stable fashion over time. I regards to what media I am using, carribsea's coarse media in the main chamber and the fine in the effluent chamber. alk this moring was 14, so it is coming back down now the the reactor is shut down for the moment

[RonD]

Thanks again to all who supplied advice. To give follow up on how things are going since the alk spike. I turned off the Ca reactor for basically a week. Alk levels came down daily on there own. I added the new skimmer in this time as well so that helped with a few of the other levels. Over the past few days the C02 for the Ca reactor has been turned back on and I have brought the ph up to about 7.0 .. still tinkering with the much lower bubble count, time will tell.. but wont be trusting the monitor so much. Added a bit of salt to get it back up to 1.025+ and cleaned the tank of any detritus and thats about it. things look happy and the spike appears to have had little if any ill effect

current tank parameters are
Calcium 400
Alk 9.3
mag 1300
phos.. little if any 0
nitrate 5
ammonia.. little if any
ph 8.3
SG 1.025