Sod's law states that if something can go wrong it will and at the worst possible time too.
When we arrived back from our trip to the USA naturally the first thing I did was to check on the tank. Everything was present and correct but some of the SPS corals looked a tiny bit off. It was nothing major, they just looked a little bit paler than usual and had less polyp extension. So instead of beginning the depressing chore of filling the washing machine with dirty holiday clothes, I reached instead for the test kits. KH is always the first parameter I check and the result immediately showed me the source of the 'issue', the level had dropped to 3.35dKH! What the.....?!! According to the ICP sample I took on the day before we left the level was 7.12dKH (just 10 days previously). The reason for this drop, as I quickly discovered, was a doser malfunction, the head that dispenses solution B (alkalinity) was no longer working. According to data from GHL there should have been 337ml left in the dosing container but in actuality there was 930ml. A quick calculation showed me that the head had stopped working 8 days ago, the day after we had left. Oddly that made me feel a little better, I would have felt much worse if it had stopped working before we went away and I'd simply not noticed.
So began the slow process of raising the alkalinity back up to a safe level once more. I switched the dosing of B over to head no.4 whilst the issue of the faulty one was addressed. It's the first time I have had any issue with this doser in over 1.5 years of use so I was a little nervous of taking it apart but I needn't have worried. As soon as the blue plastic cap was removed it was obvious what the problem was, a tiny piece of the cap had snapped off and jammed the rollers (the offending piece is shown to the left of the screws in the photo below).
Once the bit was removed using a pair of tweezers, the rollers were free to move once again and amazingly the motor still worked, I had fully expected it to have burnt out after the rollers got jammed. All that was required to get it functional again was a new plastic cap, phew!
I have since discovered that GHL considers the cap and rollers to be wearable parts and need to be replaced annually. The rollers should also be cleaned every 3 months as well which I hadn't been aware of. Oops!
Over a period of 10 days the KH was gradually increased back to normal levels and I nervously watched for signs of stress in the corals. It's been 3 weeks so far and nothing looks worse, no stripping of corals as of yet so fingers crossed I've managed to get away with the momentarily blip in the alkalinity dosing schedule.
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!