Friday, May 11, 2012
after conducting an observation on the three aquarium. we found that tank A and C were both cycled systems and that tank B had an uncycled system, it did however have a thermometre and a heater, it was also the smallest tank of the three and had the lowest ph level (6.4). i addition to this it also had alot of duckweed growing in it, again an indication of the tank being an uncycled system as duckweed tends to grow in slow moving water. also we know that duckweed germinates very quickly and if not managed correctly it could block out the light completely, which would make the tank more susceptible to algae growth. we observed that the duckweed in tank B was covering most parts of the water which could account for the murkiness of the water. the stained glass of the tank together with the flourescent light made it more difficul for us to see the extent of algae growth, although it did seem that the water was murky. this particular tank had both floating and soil plants. tanks A and C both had LED acitinic blue lights in them. we observed that tank A, which was the largest aquarium had little or no substrate mostly pebbles, there was quite alot of algae growth on the glass, and there was plants as well as different types of fish. tank C, from what we could see, had the biggest variety of plants and fish. the plant cover was so dense that it was actually hard to make out how many fish and plants there were. the group noticed that the fish were swimming at a fater tempo and were therefore more active. we found that tank B was the only aquarium to have snails in it. we concluded that while tank A seemed to be the better aqaurium because of the size and the filtration system, it was probably tank B that had the regular water changes. my personal opinion ,however, is that tank C was the aquarium with the regular water changes because despite the ph level being the same as tank A(7,2) i noticed that the GH and the KH was much less than the other two tanks. because as we all know, the water in Cape Town is quite soft, keeping that in mind when we look at the tank C: the GH was <3 and the KH was 3. if the water in the tank was being kept i the tank for a longer period of time the water would be more hard than soft. my final answer, being based on the premise that no chemicals were added to increase or decrease the hardness of the water, therefore is tank C.