lduncan

in case anyone's wondering, somatropin is highly regulated. Unlikely to get access to it here. (legitimately anyway )

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.

:-? Maybe it's the way people comprehend what I've written? Some people have vivid imaginations :lol:

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

Finally someone understands what I actually said. :bounce:

But every one has their own best road to travel on. The best road for someone with a priority of speed, will be the shortest road. The best road for someone with a priority on taking in the scenery may be the meandering scenic road. ;-) The problem is if you don't no what roads exist, and what they're like, how can you choose the best one for your particular priorities ;-) There is only ever one best road for someone. Layton

Like I said, it depends on your priorities, and what you want to keep. The best way may be different for different people. But there is always only ever one best way to do something. Layton

Depends on your priorities, and what you're keeping. But make no mistake, there is always only ever one best method.

Some of those Italian tanks at the start of the thread I think I recognise from the HGH threads on RC a while ago. This is my favourite shot out of the lot:

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

What do reactor users consider an "average" cost for reactor media (per kg)?

what's abusive about it?

Wasp plays the poor victim again. :roll: Ignorance is not a term of abuse. It's a fitting description. Do you have an alternative euphemism you'd prefer I use? How about "previously unencountered knowledge of", or maybe "heretofore unawareness of" Read Pies post. Can you can honestly say that what he wrote is not totally based out of ignorance, given this thread, and the threads linked here? It's exactly what it is, plain and simple. Abusive? Ignorance is a completely accurate description. I don't have an overblown opinion of myself at all. I think you're equating my persistence with ego. Hold up, that's not the case at all. Someone asked me a direct question as to why Eric has never mentioned the abilities of UV? I said that it's possible he's ignorant of the abilities I mentioned. You're contorting what I've said again to fit you're victimization routine again. Also, i don't see any reason why comments and writings from "experts" are not held to the same scrutiny as anyone else's comments or writings? I gave good reason why I disagreed with them. It wasn't a case of me dismissing them for no reason. :roll: No, you were the one making the comparisons. I was explaining why i'm so persistent with my posts on here sometimes. I knew when I posted that you would twist it to fit you're own purposes. Layton

there's some crap and some truth in that wet web info. been covered before in other threads. One thing I find strange is that the hobby info always tends to focus on how it kills floating stuff. No one ever seems to mention the photochemical stuff (breaking the C=C bonds) which is really the most interesting and useful result of using UV.

Anyone want to volunteer some pricing of a calcium reactor for a mid size tank, and cost of media? I have ballpark figures, but might as well make my breakdown as specific as possible.

Don't worry I'm not talking about cheap in a nasty way. I don't skimp on quality if I can help it either. Layton

TDS is only an indication. Doesn't necessarily relate to what we consider "bad" dissolved solid. For example, Mg, Na, Ca etc are all classed as TDS. But i've not had algae or cyano issues from using tap water here. I'm on the other side of the city from Tim, so we may have different supplies.

I'll approach it from a dollars and sense point of view ;-)

No I don't use RO/DI. But Christchurch is a special case really. I've never had any problems with fresh water supply. Some parts of the city occasionally have light chlorination. But if I lived anywhere else in the world, I'd absolutely be using RO/DI.

We have a winner. Most ignorant post of the year! RTFT

When you hear people talk about adding carbon sources to a tank, how carbon can be limiting, just remember that alk is carbon. Redfield says that the ratio of C : N : P is significant in determining dominace of algae species, and because N and P are near impossible to keep at "natural reef levels" (P especially), no matter how hard you may try. I prefer to run alk higher which compensates for this, to some degree, keeping the ratio closer to where it should be.

Calcium 380 - 400 Alk around 11 or 12dKH Mag around 1100 - 1200 (not as important when calcium is a little lower) remember Alk == carbon

Are you open to options other than calcium reactors? You obviously haven't spent money on one yet. I won't make any secrets about it. I think there are better, less expensive ways of keeping up alk and calcium. Say the word, and I'll give you a rundown of my opinions on what I personally would do. Layton

:lol: Is it just me or are these pink monti's really brittle. Every time i put my hand in the tank, I end up breaking off half the coral :lol: Lucky they grow fast.

You won't have an issue with growth running calcium at those levels, but there is little benefit, as far as growth goes, keeping it that high. It does increase the rate of abiotic precipitation on things like pumps and heaters though. Which can be a problem sometimes. Calcium becomes limiting over alk for calcification when levels fall below around 350ppm. So I like to keep levels around 380 to 400. Alk is the single most important water parameter for coral growth. But yeah, if people aren't adding a lot of calcium or alk daily through 2 part or a calcium reactor, it's probably a better option.