Calcium reactors and how they work

[lduncan]

Not sort of, exactly.

No, they are not exactly the same at all. They are to different measures. ppm (equivalent to mg/Kg) is mass based, as opposed to mg/L which is volume based.

mg/L is only ever exactly the same as ppm when whatever liquid is occupying the volume has a relative density of 1kg/L.

However, they can be considered equivalent for the purposes we use them for.

Layton

[Zev]

So, for us newbies with smaller tanks who don't want to spend the money on, or cannot fit a reactor or kalkwasser stirrer anywhere around our tanks, what are some other good options for us as far as keeping calcium, magnesium and alkalinity at suitable levels.

And what levels do you guys/girls try to maintain?

[lduncan]

Here you go my opinions:

My recomendation would be to forget about a reactor and get a couple of dosing pumps, and use randy's two part dosing system (http://www.advancedaquarist.com/issues/ ... 4/chem.htm). Purchase the calcium chloride and sodium bicarbonate in bulk from Medchem in Auckland (or combine with other reefers up there like cracker and others), get a couple of 25 litre plastic jerry cans and mix up several months worth of the solutions at a time. Then set the dosing pumps and forget.

2 part system can easily support very large high demand tanks. I'd wouldn't hesitate to use this systems on a 4,000 Litre+ highly stocked sps system. It can easily scale to that sort of size tank, and beyond.

Here's my justification:

First the Dollars Part:

Fixed Equipment cost:

• Calcium Reactor:
  
  • Calcium Reactor $350
    Regulator $150

Bulk automated 2 Part Dosing Scheme:

• Dual controlled dosing pump. $300 for two pumps on timers up to $800 for the cool 3 channel Grotech system with built-in controller.
  Couple of 20 litre plastic jerry cans $20

Ongoing Costs:

• Calcium Reactor:
  
  • $5 for 1kg reactor media (cheaper than I thought, high quality media seems a lot more expensive than that)
    Bottle rental $10 /month (unless you want to buy a bottle which will increase the fixed cost above)

Bulk automated 2 Part Dosing Scheme:

• $5.20 in CaCl and NaHCO3 to provide equivalent of 1kg of reactor media (possibly cheaper if you want to look at lower grades)

So comparing a more or less rock bottom price calcium reactor setup with a 2-part system, the fixed equipment cost for 2 part will likely be significantly less expensive.

Running costs are similar when using high purity 2-part components compared with what I suspect maybe cheap reactor media? Either way, for arguments sake, lets say ongoing costs are similar when you own your own bottle, but if you're renting a bottle, 2-part will win out on ongoing costs.

Now the Sense part:

Tuning:

Calcium reactors take time to tune, as it must be done using trial and error. This can take a week or so, sometimes more, sometimes less.

2-part systems don't have that issue. You can easily determine and set the dosing amounts by doing two tests 24 hours apart. No trial and error tuning, like with reactors.

Maintenance:

Calcium reactors are high maintenance. Tubes block, pumps clog and ware. Dosing pumps require far less mainenance.

Method In General:

I like to keep stuff as simple as possible. Just taking a step back and comparing how these two methods are adding calcium and alk. The reactor, you're effectively taking solid calcium carbonate, disolving it in acid environment within a cylinder which is more or less attached, and part of your tank, in order to liberate the individual calcium and carbonate ions.

As opposed to the 2 part systems where you are directly adding the individual calcium and (hydrogen) carbonate ions, no locallised acidification, or worying about excess gas. When the bottle is going to run out, retuning the reactor as media is used, tubes constrict, etc

Control:

With a calcium reactor you don't have individual control over calcium and alk.

With the 2 part systems you decide how much of each you add. This can be an adantage, as alk is not always used in the ratios which a reactor provide.

Also people who use reactors often find that every so often they need to use one or other of the 2 part chemicals to make adjustments and bring the ratios back to where they want them anyway. If you have to have these chemicals around anyway, why not use them instead of the reactor?

Another consideration is what else you are adding when you're dissolving natural calcium carbonate reactor media. Although there are low phosphate media, all natural medias release phosphate, which is yet another unecessary source of phosphate to tanks which are already loaded in phosphate. 2-part system don't add phosphate. Then there are heavy metals etc..

These are most of the reasons why I personally would never run a calcium reactor again. 2-part all the way.

Layton

[TM]

The cost of the reactor seems reall cheap? what sort is it? same with the media? what type.

[lduncan]

I know, but even with those numbers for the calcium reactor and media, which I would consider VERY cheap, (they were provided by others on here) there is still a cost advantage to the 2-part system. Especially in fixed equipment cost.

That difference will only get bigger with more middle of the road prices for the reactor and media.

[suphew]

Nice post Layton, makes some good points and after reading it I'd now consider it an option.

I don't think the cost difference is a significant issue, a couple of hundred $ either way isn't much in reef keeping terms. Also I run mag chips in my reactor as well, so would have to take this into consideration. However the main reason I wont/cant change is my sump area is pretty much full of sump and I dont have room to add two more containers. And if I did have the room I would be adding more/bigger fresh water top so I dont have to fill it every week.

[tee-em]

Nice post Layton

was wondering about pros and cons, you have laid it out nice and simple so even I undestand.

[puttputt]

Yes, good post, even with your digs at cheap reactors and cheap media :roll:

But for those looking at options, heres my routine for running my reactor.

- Saturday morning - wonder over to tank, adjust drip rate to fast - Time taken 10sec.

- once a year, change media.

Its a pain i know!

[jetskisteve]

U forgot the cost of RODI to mix all the 3 part, Nick uses the 3 part on his system at home HEAVILY stocked sps 2000L and mixing the chems is a PITA he go's thru heaps of it using an Aquamedic triple dosing unit.

[lduncan]

U forgot the cost of RODI to mix all the 3 part, Nick uses the 3 part on his system at home HEAVILY stocked sps 2000L and mixing the chems is a PITA he go's thru heaps of it using an Aquamedic triple dosing unit.

You forgot that you'd be using that same RODI to topup anyway. So you actually don't end up using more RODI that you would with a calcium reactor anyway.

[lduncan]

Yes, good post, even with your digs at cheap reactors and cheap media :roll:

Not really. Those prices are a lot cheaper than I have come across. But anyway.

But for those looking at options, heres my routine for running my reactor.

- Saturday morning - wonder over to tank, adjust drip rate to fast - Time taken 10sec.

Do you have to adjust it every week?

- once a year, change media.

Its a pain i know!

You know there is far more maintenance involved with a calcium reactor than just that ;-) Far more things which can potentially fail, wear and need replacing.

[lduncan]

Nick uses the 3 part on his system at home HEAVILY stocked sps 2000L and mixing the chems is a PITA he go's thru heaps of it using an Aquamedic triple dosing unit.

How much does he mix at once? How much does he go through in a day?

[jetskisteve]

He mixes 20L of each at a time & not sure on dose rate I'll ask

I see your point Layton but I'll stick with a reactor like PP I adjust the flow weekly & change the media annually (maybe) and parts for them are cheap the only thing to break is the impellor?

[puttputt]

What other maintenance Layton, I have had mine running for 12months, and thats it, no other maintence. And yes evry week i have to turn a little tap on - 10sec evy week, 52 weeks a year - 520 seconds a year, time wasting I know.

And Suphew reckons that with a better reactor, you don't even have to do this.

As for things failing and wearing out, I wait and see.

Not saying there is any thing wrong with the way you do it, but there are other options that require less work.

[lduncan]

Not saying there is any thing wrong with the way you do it, but there are other options that require less work.

Less work? how?

[puttputt]

But for those looking at options, heres my routine for running my reactor.

- Saturday morning - wonder over to tank, adjust drip rate to fast - Time taken 10sec.

- once a year, change media.

Its a pain i know!

[Pies]

I use a CA reactor. I can't image a cheaper or less fuss way to do it. Turn it on, tune the bubble and drip rate, leave for 9 months, refill and repeat. Re-fill the CO2 every 7-8 months. A bucket of media costs bugger all.

Layton - i'd actually try to try the method you are using, to see if it give me different/better growth/colour. Are the ingrediants easy to source? How much would I need to use a day for my tank (2500 litres). I have often woundered if a mix of using both might be more ideal than just one or the other?

Pie

[lduncan]

Layton - i'd actually try to try the method you are using, to see if it give me different/better growth/colour. Are the ingrediants easy to source?

Yes, easy to source MedChem in auckland is the popular supplier.

How much would I need to use a day for my tank (2500 litres). I have often woundered if a mix of using both might be more ideal than just one or the other?

How quickly does your tank go through 1kg of reactor media? I can work out from that roughly how much you'd be adding if you were to use a 2-part.

Also, you might be surprised in the difference between a Calcium reactor, and 2-part, especially the differences in CO2 levels, as well as "contaminants" added.

For me, the cost thing isn't so much of an issue, as the reliability, simplicity, safety, control, and what i'm actually putting into the tank is.

[Pies]

I use 2 buckets of media a year, which are either 5KG or 5L.

CA reactor couldn't be any easy to run, but I am thinking of using both for a while just to see how it goes. Suphew has expressed interest in it so we might go halfs in a brew and see how it goes.

My growth is excellent, and I am forced to throw corals out or put them in places and let them die. But I wounder if it will change the growth (skinners/fatter) or whatever.

Pie

[wasp]

I used to use dosing pumps, dosed calcium alkalinity & magnesium all automated with a 3 way IKS. The system has merits but the downside was always having to hassle around mixing chemicals.

Eventually bit the bullet & went calcium reactor, the downside of this (at first ) being the extra Co2 in the tank. Now though I've got the Co2 sorted.

For me anyway, the reactor is easier, in fact I can remember feeling the "burden fell off" type feeling after setting it up, the reactor is also tidier without so many bottles etc.

However both systems are good I don't really see the point of big arguments over it.

[wasp]

But I wounder if it will change the growth (skinners/fatter) or whatever.

Pie

Depends how you manage the Co2. IMO running a reactor at night is detrimental to growth as it lowers pH and therefore growth. However it can be a plus during the day as Co2 is required for photosynthesis. My Co2 regulator has a solenoid on a timer it is turned off overnight, this system seems to work very well.

[puttputt]

You can counter the ph drop at night with a reactor, by using kalk water for your topup at night. (I do, and need to run 24/7 to keep up with demand)

[wasp]

Yes that is an excellent option, pluses all round for a number of reasons.

It's been posted before but here is an article showing some of the benefits of this

http://www.reefscapes.net/articles/bree ... asser.html

[lduncan]

However it can be a plus during the day as Co2 is required for photosynthesis.

I don't think that's a plus at all. CO2 can slow calcification.

One of the sybiotic relationships of the zoox / coral, it that the coral provides CO2 to the zoox from the corals respiration. They don't need to get any extra from the water.

[JDM]

Can someone please explain to me the way to use kalk as top off? I am about to get my tunze auto top off running and would like to combine this with kalk, I would like to diy somthing, rather than get a stirrer, but if the stirrer is the best thing then I will do that.