Dealing with evaporation from a reef tank can be a real chore if you haven’t got a robust system in place and there’s also a pretty high element of risk involved if your chosen system isn’t up to scratch. For a start, it could fail to keep-up with demand (in which case a low water level could expose equipment and lead to a system failure), or at the other end of the scale, overfilling could make your tank literally ‘runneth-over’ (causing untold damage and recrimination). In either case your Salinity is also going to be ‘all over the place’ too, stressing livestock, possibly to death…. in short this is one area where cutting-costs can come back and ‘bite you on the bum’!
Having started-off with the ‘religiously-trickling-in-a-jug-of-RO-every-day’ method back in the day, we’ve since been through a few different systems, each progressing in complexity. Our second system was a simple peri-pump on a timer which delivered Kalkwasser during the night (and which worked fine but couldn’t cope with seasonal fluctuations very well) and next we experimented with float switches… briefly. Finally we graduated to an optical system with a back-up float switch which is what we’ve been running on the Black Tank for a couple of years now. At the risk of tempting fate, this system has worked flawlessly, although it does have its ‘nuances’. Move on to the not-so-distant past and, during our research for the set-up of our new test system (the White Tank), we noticed another interesting option… this time from high-end operation Elos. Going by the moniker ‘Osmocontroller’, this system had overall good feedback and we were therefore keen to give it a go.
On arrival, the Osmocontroller is neatly packaged in an oblong box which has an outer slide-off sleeve. Inside we have a number of components… the control unit, sealed top-up pump, USB-probe cable, bracket, plus screws, fixings and instruction booklet. Everything apart from the tubing to connect to the pump for water delivery is present and correct and feels well-made, especially the tiny and neat control box, so we go straight into the installation of the system. One note about the tubing required… we decided to go for a 9mm outer bore, 7mm internal bore solution rather than the 9mm internal bore suggested by Elos. This narrower tubing slides inside the pump outlet, rather than over it, and is more suited to our 170 litre system in our opinion.
One slight issue we have is probably down to the distance we have our top-up reservoir away from the sump indeed the probe cable length comes up short of the 3m we require. The line connecting the controller to the pump is actually long enough to make-up the distance but we want the controller right next to the reservoir, not dangling half way between it and the tank. Luckily, the fix is simple in the form of a USB extender cable.
So… having procured the extra bits and bobs necessary, we finally complete our install of the unit. We’ll be totally honest, the bracket holder for the probe is pretty basic at this price level and it is easy to knock it out of position. That said, once the installation is complete, if it is sited well out of harm’s way, it isn’t a problem. Of course you could probably DIY something if necessary… maybe superglue a cable tie or clip onto an algae magnet to hold the probe? it all depends on your circumstance really. On a positive note, the footprint of the probe is extremely small so it could fit in even the tightest spaces.
In operation, as said, this device works on a slightly different principle to all those we’ve already mentioned. Based on a patent US number 8747075, this system is rather innovative, relying on the probe to sense a change in temperature to activate the supply… not as you might think a drop in temperature from becoming exposed to the air though, rather the probe actually produces a small amount of heat internally which is dissipated while it is submerged. On exposure to the air, the probe actually heats up and this triggers the pump. Also slightly different is the fact that this unit is restricted in its delivery and will only ‘check’ to see if dosing is required every 15 minutes and will then deliver a fixed 100ml dose each time. In operation we’ve found this means the unit is in active top-up mode pretty much all the time (green light flashing) although it does seem to keep up with demand on our test system (130litres). Actually even a drop of just 1mm or so is enough to activate the pump, so it is capable of maintaining excellent stability. In the event of a fault such as an empty reservoir, a damaged pump or kinked tube, the microprocessor will recognize this and a red alarm LED will indicate the problem while stopping pumping until the problem is fixed and the controller can be reset. The last thing we’ll add is that the incorporation of a manual button on the controller to activate the pump manually is very useful and could be adapted to a variety of tasks which makes the controller rather versatile!
With an RRP of £149 (at the time of writing) this is a ‘high-end’ system offering excellent failsafe options and, in our experience, reliable operation. The components are all very modern and extremely compact… in short, it’s a system that is well worth considering if you are wanting an effective to automate your water top-up requirements!