It’s finally August! Time to relax on the beach, host a few BBQs, and of course celebrate National Water Quality Month!
Ok, so maybe August isn’t exactly synonymous with water quality for most people. But here at Ripley’s it’s always a top priority. As a member of the aquariums husbandry department and the aquarist in charge of our chemistry lab, I am responsible for testing and monitoring the water quality of our exhibits. Frequent and meticulous testing is critical to ensure that our exhibit water meets the highest of standards. The lives of our animals literally depend on it.
When we take care of aquatic animals, we do so in part by controlling their entire environment!
The water in their exhibit, for all intents and purposes, is their whole world. There is no current to flush waste away, no distant reef to retreat to, but rather a finite, and when compared to the size of lakes and oceans, relatively small volume of water that must be pristine. If left unchecked, waste and other potentially harmful contaminants could accumulate to levels that threaten the well-being of our animals!
But alas, there is no cause for concern. We have a dedicated laboratory for the sole purpose of testing water quality parameters to ensure they are always within the appropriate range that our animals need to thrive.
Now let us be clear, this is not like testing the pH and alkalinity of your pool or using a testing kit for your aquarium at home. Our lab is equipped with high-end scientific equipment to make certain we get accurate and precise results. Routine testing involves the use of multi parameter meters, pH/conductivity/luminescent dissolved oxygen probes, incubators, burettes, and the pièce de résistance, a UV/Vis spectrophotometer with an added on flow thru apparatus.
With this equipment we are able to measure, and thus closely monitor, the pH, salinity, alkalinity, oxygen saturation and oxygen content, levels of nitrogenous waste products, potential heavy metal contaminants, chlorine content, phosphate levels, and bacterial growth in our exhibits. Among other important parameters. We test our water constantly as early detection enables us to correct potential issues within our exhibits before they progress to the point were they pose a threat to the well-being and health of our animals.
Alright, I have delayed long enough. It’s time to talk about poop!
As you may have heard everyone poops, and this includes all of the animals here at the aquarium. So, where does that poop go exactly and does it affect our water quality? Some of it is removed as part of the mechanical filtration included in the life support systems for our tanks, more is removed by chemical filtration, and yet more during routine cleaning by siphoning and gravel vacuuming etc. But that doesn’t get rid of all the waste produced by fish, namely I’d like to focus on the nitrogen waste product – ammonia. Specifically, how we prevent it’s build up and how we test for it.
Ammonia accumulation is toxic to all vertebrates primarily due to its neurotoxic effects. In the open ocean, the concentration of ammonia never has the opportunity to suddenly spike because of just how massive oceans are. But in closed recirculating systems like our exhibits, ammonia levels have the potential to climb and to climb rapidly. To prevent this we use biological filtration which involves the help of nitrifying bacteria that actually use the ammonia as an energy source. These bacteria “eat” the ammonia which prevents it from building up to harmful levels.
But in order to ensure this beneficial bacteria is doing its job we have to do ours too.
This involves testing exhibit water for ammonia. For some tanks this means daily testing and for others a couple times a week. We test for ammonia and other nitrogenous waste compounds using colorimetric assays. As part of these assays, a dye or colour change is produced following a chemical reaction between our laboratory reagents and the waste compound we want to measure. The intensity of this colour being proportional to the amount of ammonia (in this example) present in the water sample. In the absence of ammonia, no colour change will occur. This colour change is measured using a spectrophotometer and offers precision home testing kits cannot replicate.
We are very conservative in our cut off for what constitutes safe levels of ammonia and other contaminants. We will perform water changes, replacing tank water with new water free of contaminants, whenever these limits are exceeded. Again, if ammonia would not accumulate in the oceans why should we tolerate ammonia accumulation in our tanks!
This abundance of caution helps to ensure our tanks don’t only look appealing to our guests, but the animals in them are happy and healthy too.
P.S. Happy Water Quality Month!