Keep it Balanced.
One of the most import considerations when it comes to maintaining calcium and carbonate levels in the reef aquarium is, that whatever method is used, it must be a balanced one. Corals need calcium and carbonates to be available in a particular ratio in order to build a healthy calcium carbonate skeleton. If this balance is not maintained the consequences can present themselves as a difficulties in maintaining pH, calcium, and carbonate levels. For a supplementation to be described as balanced it needs to be providing something in the region of 20 ppm calcium along with 2.8 dKH (1meq/l) carbonates.
Many of you of course will be familiar with liquid supplements for calcium dosing but probably think of them as being pretty basic stuff only suitable for beginners. In fact liquid supplements for maintaining calcium and carbonates can be very sophisticated products, superior in some ways to the more technical solution offered by calcium reactors.
Although there are plenty of different supplements for both calcium and carbonates on the market, many of these are unsophisticated products that will replenish calcium or carbonates but with long term use result in ionically unbalanced water. This can be particularly dangerous if water changes aren’t carried out on a regular basis. With no water changes, levels of sodium and chloride from these supplements can build up producing water that’s more like a solution of table salt than seawater!
There are three types of liquid calcium supplements of real interest to us, these are the ionically balanced two part supplements, the Balling Method, and what I would describe as hybrid systems which seem to combine elements of the first two. The theory behind all of these methods is fairly similar as they all aim to add calcium and carbonates in a balanced manner, the differences tend to be in terms of how associated ions, minor and trace elements are included into the dosing regime.
When using any of these systems I’d advise keeping a watch on the salinity of your reef as one side effect of these various methods can be an increase in salinity. With use it will soon be apparent how much the salinity is shifting and you can then work out a simple solution to correcting the problem, for example every so many days or weeks removing a given volume of water from the aquarium and replacing it with fresh RO.
This system of calcium replenishment was originated by Hans-Werner Balling and first published in 1994. Essentially the system consists of dosing calcium chloride and sodium bicarbonate as separate solutions in a strict ratio but as the chloride and sodium ions are not used in the aquarium, a third additive is required to balance out what would otherwise produce an increase in salinity. This third solution added to the aquarium is, in effect, a sodium chloride free sea salt mix that brings with it many minor and trace elements.
A comparatively recent introduction, a kind of ‘lazy reefkeepers’ version of the the Balling Method that dispenses with the use of sodium chloride free sea salt mixture and relies instead on regular water changes to control salinity increases.
See; EcoBalling Method.
Two Part Balanced Ionic Supplements
These two part systems are designed to add calcium and carbonate, along with their associated ions in a manner mimicking the natural ionic ratios of seawater. The calcium component will include some or all of the following ions (depending on manufacturer): bromide, calcium, cesium, chloride, chromium, cobalt, copper, iron, lithium, magnesium, manganese, nickel, rubidium, strontium, zinc. While the carbonate component will include some or all of the following ions (depending on manufacturer) bicarbonate, borate, carbonate, fluoride, iodide, molybdate, potassium, sodium, selenate, tungstate, vanadate. Overtime you’ll register a slight increase in salinity as, in a sense, it’s almost like dosing with a concentrated sea salt mix.
A number of manufacturers produce what I’d describe as hybrid systems, they’re not Balling Method and neither are they strictly a two part solution.
They tend to consists of three to five parts parts – two of them being a two part calcium/carbonate additive with the additional parts being various trace element mixtures which, like the calcium and carbonate additives, need to be dosed separately.
Better Than a Calcium reactor?
Well yes and no.
Liquid dosing doesn’t introduce any phosphate into your reef system, whereas a calcium reactor, depending on the quality of the media being used, can be the source of unwanted levels of phosphate.
Liquid dosing won’t alter your pH, although it may help support it, however a poorly set up calcium reactor can easily lower the pH of your reef.
Liquid dosing can often be an almost complete source of supply of minor elements and trace elements.
Liquid dosing will contribute far more available calcium than calcium hydroxide (kalkwasser).
For covered aquariums where there’s not enough evaporation to allow kalkwasser dosing or for reef tanks where there’s no sump space to allow for a CO2 reactor, liquid dosing can be the best solution to calcium replenishment.
Knowing the calcium demand of you reef you can easily calculate the required dosage from the manufacturers product information; usually the manufacturer will tell you how many mg/l calcium is provide for a give dose. Getting the dosage right with a calcium reactor can involve making a lot of adjustments to flow rates at the same time as performing a lot of calcium and carbonate testing before determining the correct settings for your reef.
Manual liquid dosing can be a more economical solution for smaller reefs, or reefs with a lower calcium demand where a calcium reactor might seem to represent expensive overkill. As the size of the reef system or the calcium demand of the corals increases the cost of the supplements used for liquid dosing can become high compared to the running costs of a calcium reactor (replacement media and CO2).
Calcium reactors are expensive items of equipment to purchase but the running costs are low.
Both forms of calcium reactor, kalkwasser reactor and CO2 reactor, can constitute very real dangers to your reef if they go wrong and are also potentially dangerous to you the aquarist. Calcium hydroxide is a very caustic powder that should be handled carefully and kept away from children and pets. Carbon Dioxide (CO2) is kept in pressurised cylinders which if mishandled may explode.
Ultimately the answer may lay with combining the two methods to get the best from each.
How to dose manually.
Some manufacturers may suggest leaving a minimum time between dosing the separate parts (say 20 minutes apart), whereas others may just say to dose the separate parts into a high flow area of the aquarium.
Always follow the manufacturers guidelines. Though, having said that, when instructions are given for weekly dosing there are benefits to be had if you pro rata the recommendation to a daily dose.
Automatic dosing involves the additional cost of purchasing dosing pumps but brings with it a number of advantages.
Once your dosing regime is set up or programmed you can forget about the hassles of having to remember when to dose and with how much. Maintenance becomes a matter of replenishing each part of your supplement as they become exhausted. Depending on the demand of your reef and the volume of the containers holding the individual solutions you can go some time with out having to pay attention to calcium dosing. Nevertheless, I’d recommend checking calcium and carbonate levels each time you restock. There are two reasons for periodically measuring calcium and carbonate levels. Firstly, to ensure you’ve accurately calculated out the correct dosage and that the pumps are operating as desired. Secondly, now you’re making appropriate quantities of calcium and carbonates available at a near constant level, you’ll most likely find that as your corals benefit from this, that they’ll grow and hence the demand will increase.
Liquid supplements can be easily added to the aquarium automatically by using dosing pumps. This is usually done by the use of peristaltic pumps.
These pumps consist of a casing, a rotor, and a length of special hose. The rotor has two or more short arms ending in rollers, as it rotates these rollers squeeze the hose against the housing in turn, as each roller squeezes the hose it pushes a small volume of liquid along the length of the hose and through the pump. More expensive pumps can be programmable, while cheaper, non-programmable pumps can be controlled by using an aquarium computer system. Most domestic timers will be unsuitable for this application unless they’re capable of switching dosing pumps on and off for timed periods of a minute or less.
A separate container is required for each different component being dosed; the pump then draws the solution from the container, through the pump, and feeds it into the aquarium. This is all done through 6mm diameter airline tubing and it’s usual to employ an airline check valve somewhere along the line to ensure efficient delivery. Depending on the make of your programmable pump you can alter how may times a day it’ll dose and how long it’ll dose for. Most of these pumps have a fixed dosing rate so it’s the length of time the pump is working throughout the day that’ll control the volume of liquid dosed. If the pump has a dosing rate of 3l/hr and we want to add 50ml a day that represents a running time of only one minute, so it may well pay to dilute the liquid with RO water to allow repeated dosing throughout the day.
The various feeds from the doser should be delivered into a high flow area and, if the pumping system is going to deliver more than one component at a time, should be spaced apart accordingly. Perhaps a minimum spacing of 10 cm between dosing locations.
Hints and Tips.
Most importantly, remember to never mix the calcium and carbonate components of any of these multi-part liquid supplements together in a container prior to dosing. You’ll just end up with calcium carbonate in a form that’s not accessible to your corals.
If it appears to start “snowing” in the tank after the addition of the calcium and carbonate liquids this means calcium carbonate is being precipitated out of solution. You need to either dose further apart or into a higher flow area of the tank. It may also be worth double-checking your calcium levels to make sure you’re not in a state of calcium supersaturation.
Before starting to dose with a balanced liquid supplement it’s advisable to ensure that your calcium and carbonate levels are at, or near, to the correct levels for a reef tank. Somewhere in the range of say, 380 – 440 ppm calcium 7 – 11 dKH.
If you’re dosing automatically, using peristaltic pumps, then I’d recommend that you break up the daily dosage into a number of smaller doses to be administered throughout the day. This way you can minimise fluctuations in the calcium levels and offer a steadier environment, reflecting the constant levels found on the reef in the wild.
Correcting Calcium and Carbonate Levels.
Your calcium and carbonate levels can be out of balance in a number of different ways, each requiring a slightly different method of correction.
- Calcium and carbonates too high: – discontinue all forms of supplementation and wait for the levels to naturally decrease. Monitor regularly.
- Calcium and carbonates too low: – add balance liquid supplements at a slightly higher dosage than recommended. Monitor until acceptable levels are reached and then cut back on dosage until maintenance of required levels is achieved.
- Calcium too high, carbonates too low: – add carbonate component only. Monitor both parameters until back in target range.
- Calcium too low, carbonates too high: – add calcium component only. Monitor both parameters until back in target range.
- Calcium at target level, carbonates too low: – add calcium component at lower dosage, say 50% and add carbonate component at double dosage (don’t exceed manufacturers’ recommended maximum dose). Monitor both parameters until back in target range.
- Calcium too low, carbonates at target level: – add carbonate component at lower dosage, say 50% and add calcium component at double dosage (don’t exceed manufacturers’ recommended maximum dose). Monitor both parameters until back in target range.
How to Calculate Dosage for Automatic Dosing.
If the peristaltic pump you’re using has a typical dosing rate of 3l/hr that equates to 3000ml/hr or 50ml/min. To find how long you’d need to run this pump to dose a given quantity, divide the required dose in ml by the dosing rate.
Example 1: if you want to add 50ml a day, divide 50 by 50, this gives you a figure of 1 representing a running time of one minute.
Example 2: if you want to add 25ml a day, divide 25 by 50, this gives you a figure of 0.5 representing a running time of half a minute or 30seconds.
As you can see we are dealing with small dosages and short time periods, so it can pay to dilute the liquid with RO water to allow repeated dosing throughout the day. Take any dilution into account when calculating out your daily dosage.
Example 3: if you take the dosage from example I above and dilute it 1:1 (50ml RO + 50ml supplement) you’d then need to dose 100ml per day, doubling the pump run time to 2 minutes to deliver the required amount of supplement. This extended running time can then be spread over the course of the day by breaking the dosing down to 1 minute twice a day, 30 seconds four times a day, or 15 seconds eight times a day.
Example 4: example 2 above would really benefit from dilution. By diluting 3:1 (75ml RO + 25ml supplement) you could then dose the same number of times as in example 3.
©2009 – 2011