unbalanced alk to cal need advise pleaseee

[chuckbuc]

ive been having an issue for quite some time now and i can figure out whats going on and y ..i am using a calcium reactor to supplement my alk and calcium to my 450 gallon mixed reef (sps heavy)..these are my numbers
alk 8.3
cal 560
mag 1400
Potassium 390
i cant seam to figure out y my calcium is so high.i check every batch of water change water i have done in the past 3 months ,calcium has never been over 450 with the new seawater .i dont dose any other calcium additives .how could i be so unbalnaced from alk to cal ? ..i was using the reborn cal media ,i just switched last week back to carbi sea media .thinking maybe the reborn was maybe higher in cal ,is that possible? I have also measured my alk and cal coming out of my calCium reactor this is what i got
effluent alk 23 dkh (8.20 meq/l)
Effluent cal 760
also i am running a sulfer based denitrator ,im not sure if that has any effect on anything .any advise would help as me and a few local reefers are trying to figure out y my tanks cal would be so high when my alk has been steady for months ,all my corals look good ,growing ,not stressed .ive used a bunch of diffrent test kits to rule out a test kit being wrong ...

[Realposition]

Was calcium lower before you put the calcium reactor online? The cal and alk coming from the reactor should be balanced vs consumption but if cal was high when you dialed your reactor in (based on alk consumption) it will always stay high. Really the only options are big water changes with a lower cal salt mix, shut the reactor off and manually dose just alk till cal comes down or just ignore it if its not causing issues

[chuckbuc]

Yes this has happened to me a while ago ,same situation ,i then turned off my calcium reactor and hand dosed alk only ,the calcium them dropped to balanced levels after a few weeks of hand dosing .once i had my alk balanced to my calcium i then turned on my cal reactor back on ,and it climbed back up .i was using using the reborn media.at that time ..reborn media is actually a peice of coral skeleton the carbi sea is more of a live rock like aragonite ,im wondering if maybe the reborn has a higher concentration of cal then the carbi sea media ?i think my next move is to do what u said shut down the cal reactor again ,hand dose alk,use i/o salt so its low in cal, and test every batch before i do a water change to make sure my water going in is mixed right and the cal is good

[tmz]

also i am running a sulfer based denitrator .

Yes the reaction of sufur bactreria uses alkalinity and not calcium. So, dosing via a calcium reactor is balanced but over time dosing only that way to keep alkainity up for the aquarium will result in unused calcium. How much depends on the size of the sulfur bed in play .
530ppm calcium won't hurt anything ,ime; but it will likely go higher overtime. I'd dose some baking soda ( bicarbonate) to make up for the alk being taken in the sulfur reaction. It will take some tinkering to figure out how much you need in your set up.

[chuckbuc]

Really so what do u do then ? Do u also supplment alk on top of the cal reactor running ? That means my cal will always be unbalanced then

[tmz]

I'd reduce the output of the calcium reactor a bit by using less CO2 and dose some baking soda( sodium bicarbonate) or baked baking soda( soda ash / crabonate) to the aquarium to get the same alk you now get . This way you make up for the alk used in the sulfur reaction and reduce the calcium input from the calcium reactor.

Salt mix plays a role too via water changes . Some are high in calcium .

[chuckbuc]

Got u ,so lower the cal reactor .my alk is usually 8.3 with the cal reactor ..i now dose alk to see if i can bring up the alk to 9 .i wonder if the cal would drop if u raise alk up

[tmz]

This is the reaction for a sulfur dentrator :

This is what happens
11 S + 10 NO3- + 4.1 HCO3- + 0.5 CO2 + 1.71 NH4+ + 2.5 H2O

--->

0.92 C5H7NO2 +11 SO4-- + 5.4 N2 + 9.62 H+

Note 4.1 HCO3 ( bicarbonate) is used for every 10 NO3 .

[chuckbuc]

Dude thats chinese to me man lol .

[tmz]

Got u ,so lower the cal reactor .my alk is usually 8.3 with the cal reactor ..i now dose alk to see if i can bring up the alk to 9 .i wonder if the cal would drop if u raise alk up

Raising the alk would only drop the calcium via increased consumption of calcium carbonate via enhanced growth of calcareous organisms using more alk and calcium or on the down side upping the alk to 9 dkh might cause a biotic precipitation of calcium carbonate .

[chuckbuc]

Ok so would u say i would be better off using dosers and a 2 part over a cal reactor for my situation .?im going to do what u said and lower the bubbles which would raise the ph in the reactor ,then hand dose alk to make up the difference

[tmz]

Either way should be ok . The two part dosing won't drop pH ,the way a calcium reactor does,though. The sulfur reactor also adds H+ dropping pH.

[chuckbuc]

So if u had my numbers would u just leave it .maybe im better off leaving every thing the way it is ? Alk at 8.3 cal 560

[tmz]

I think a range of 400 to 480 ppm calcium is better . 580 is pretty high but likely won't hurt anything. It will likely continue to rise though with the sufur denitrator in play.

A range of alk from 7 to 11dkh and calcium from 380 to 450 or so is acceptable. Beyond that a precise balance isn't attainable or useful, imo.

[chuckbuc]

Ok i will play with the reactir and lowere the alk and cal alittle ,

[Eyore]

Is it me or do those effluent rates appear unbalanced?

Surely for +15dkh there should be +105ca?

So ca should not exceed 635 out of the reactor

[chuckbuc]

Yes out of the cal reactor seams unbalnaced to me also ,cal is still high ,i think maybe because the water feeding the cal reactor is high to begin with ,because my tank cal is high 560..i could be wrong but thats what im thinking

[dkeller_nc]

It's pretty much impossible for the output of the calcium reactor to be "unbalanced" in terms of calcium and alkalinity presuming that the media is all calcium carbonate. The only other possibility would be if the media contained a substantial fraction of calcium sulfate, and without looking it up (too lazy this a.m.), I'm thinking CaSO4 isn't soluble in seawater at the typical pH of a calcium reactor.

Nitrification (conversion of ammonia to nitrates) consumes alkalinity; denitrification (conversion of nitrate to nitrogen gas) produces alkalinity. But that's denitrification by bacteria in anoxic areas of the sandbed/live rock. The reaction that Tom posted indicates that sulfur denitrification also consumes alkalinity rather than producing it (I'll have to wrap my head around that, it's way too early to do electron accounting in chemical reactions).

So it may simply be that your setup (sulfur denitrification reactor) and the natural consumption of organics by bacteria to produce nitrate has the net effect of consuming a good deal of alkalinity, and it's therefore necessary to supplement carbonate alone to make up for this.

[tmz]

The sulfur bacteria T. nitrificans ( C5H7NO2 in the equation) are facultative chemolithoaurotrops. They take C for biomass from inorganic compounds CO2 and HCO3 and energy from oxidizing sulfur to sulfate(SO4 in the equation). they don't use organic carbon for the most part. They assimilate some N and process some out as N2 gas. The net result among other things is a reduction in alkalinity ;and increase in sulfate and a reduction in N overall and NO3 in particular.

Anyway in simpler terms for this disussion , they use alkalinity and not calcium

[tmz]

A calcium reactor with typical aragonite media may be a little off from the 20ppm calcium to 50ppm carbonate balance due to a small percentage of other elements in it like magnesium, PO4 and so on but not enough to account for the high calcium level posted,imo.

Most who use sulfur reactors find it necessary to supplement additional alkainity. Some do that by passing the low pH effluent through a column of calcium carbonate which nets a limited amount of alk but also adds more unneeded calcium. IMO, it's better to just dose enough carbonate/bicarbonate to make up for the alk used in the sulfur denitrator.

[tmz]

Yes out of the cal reactor seams unbalnaced to me also ,cal is still high ,i think maybe because the water feeding the cal reactor is high to begin with ,because my tank cal is high 560..i could be wrong but thats what im thinking

The addition of calcium and alk will be balanced. It will add to the amount in the water coming in as you suggest.

[chuckbuc]

So i got some 2 parts alk mix and i have lowered my calcium reactors ouput and i am now hand dosing alk only .i dont really want to shut the cal reactor fully off ,i have alot of sps and i dont want things to swing around to fast for me .do you think this will work and the calcium will lower by the way im going about doing this .a am also doing 30 gallon water changes with reg i/o salt which should help lower the cal

[tmz]

It might take some time for the calcium drop to show up.
Do your best to keep the alk steady at the 8.3 you run now .
When you dose the baking soda or soda ash don't use too much at once; ie keep any alk jump to a minimum ; lower than 1 dkh per day ,particularly with sps. Once you know how much you need to balance off the slufur ddintrator automated dosing may be ok. Personally. I'd keep it manual for awhile.
I'd chcek the calcium level in the salt mix too.
LEt us know how it plays out.

[chuckbuc]

Thats my plan tmz .i did get my alk up to 9.0 hand dosing over the last 2 weeks and ive been keeping it between 8.6 and 9.0 hamd dosing and slowly lowing my cal reactor .i will also test my new water foing in and every few days my alk and cal out of my effluent ..thanks for the help

[tmz]

You are welcome. Good luck.

[chuckbuc]

I feel like a rookie asking alk and cal questions but this has been puzzling me and a few pretty experienced reefers buddys for a while while now

[tmz]

I always feel like a rookie and try to learn new things from the experience of others,studies and science.
All of us have more to learn than we can possibly know; that's part of the satisfaction from the hobby.