The Thing About Dosing That Troubles Me.

I auto-dose two part. It seems consistent and stable for the most part. What I'm not sure I understand is the destructive feedback loop.

On occasion, my corals seem to have a bad day. The bad day causes them to stop taking up Alk. That in turn causes the Alk to increase which makes their day worse. I feel like if I only test once a week, my tank could easily careen off course between tests.

Is this just a new tank thing? Are bigger colonies more stable? Would a calc reactor offer some protection against this risk? Is it a risk?

 

Following.

 

I'm having some similar issues. My tank has been up since March. I just started dosing about a month ago since I've been adding some SPS frags and larger LPS. I'm using a dosing pump which does ALK and CA separately through out the day. Each dosing cycle is 4 hours apart. I've been testing Mag, Alk, and Ca consistently and can't seem to get my Ca up. Mag has been at 1350 - 1400 for the past three weeks. Alk has been between 9.1 and 8.7. Ca is 350 - 370. PH is between 8.45 - 8.55. I would like my Ca ideally to be at 420 PPM. I'm dosing three times as much Ca as Alk and the numbers are still pretty consistent the levels above. Looking for some advice on dosing BRS two part solution. Is dosing way more Ca solution normal?

 

Use this. This should help. Mag should be 3x your desired calcium level, if mag is to low your cal will never move and make sure u adjust alk

http://reef.diesyst.com/chemcalc/chemcalc.html

 

Jrawsky I would double check mag levels. With mag that high you should be able to control your levels fairly easy. 1350 is pretty good and allows for controllability of levels. I would do a good water change retest cal and try to adjust.

That calculator i added in the previous post should help u out.

 

A calcium reactor would not help. It's designed to consistently dip in calcium and alkalinity and a defined rate. It doesn't dose based solely on when coral take in each component. it doses at the rate you set the effluent drip and pH.

 

I'm going to retest my Mag tonight and do a 10% water change this weekend. I've been reading a lot of articles (mainly from here http://reefkeeping.com/issues/subject/chemistry.php). I'm going to lower my Alk and Ca dosing back to equal lessor doses and see if I can buffer the PH down to 8.2 - 8.3 consistently. I'm going to look into additional CO2 aeration. If I can't get that to work I'm going to dose small amounts of distilled vinegar. Ideally, I would like to have to not dose to buffer PH but using a two part solution and potentially not being able to add CO2 this might be my only option.

 

Right now I dose 2x the ca to alk. It has been as much as 3.5x ca to alk to keep levels stable. Just have to test a lot and adjust accordingly.

 

Yeah I've had similar problems with calcium reactor and dosers.
Could be a number of things but I did have red bugs and flatworms so do an inspection.

 

Your PH is pretty high, as is your alk. The alk level of natural sea water is 7. I believe that your elevated alk level compared to the ca is causing abiotic precipitation of the calcium. Check out your heater... Does it have a white calcium film? That's a good way of seeing if your calcium is precipitating. I'd try not dosing the alk for a while to see if that stabilizes your levels.

How big is your tank, and how often and how large are your water changes? What salt mix are you using? For instance, instant ocean reef crystals mixes at a Dkh of 13! There's really no reason to bump alk in your tank over 7-8. Many people find that dosing is not necessary with regular water changes.

Right now, with the dosing and correcting you are making your parameters fluctuate all over the place, which makes it hard to know how dosing is really effecting your tank without a baseline reading. Do you remember what that was, and why you began to dose?

Sorry for the rambling post.

Helen