Cougra
Well-Known Member
Before you start getting all nit-picky on the exact number of times the water in the tank gets “turned over” I think it’s more important to understand WHY you need turnover to begin with!
Reasons for HIGH turnover:
One of the most obvious and important reasons for having good water movement in a tank is for gas exchange. Due to the nature of saltwater and the temperature we keep them at it is hard to keep the oxygen levels high for the animals. A build up of CO2 in the system has an extra disadvantage of driving the pH down in the tank and eventually exhausting the alkalinity.
With the large amount of rock generally found in a SW tank, you are faced the problem of debris getting caught up in all the small places in and around the rocks. To prevent this from happening it's important to provide a lot of random water movement in the tank. Ideally, this random water movement will carry the debris away from the rocks and towards an area in the tank where it can be easily removed through vacuuming or using a mechanical filter before the water is further processed.
A lot of harder to keep LPS and SPS coral (and thus reef fish) are found in areas were there is a lot of turbulent water flow coming at them from all directions. Corals have come to rely on this turbulent water movement for a food source and to slough extra slime, decay and debris from their tissue. Without this valuable service then animals will not be able to photosynthesize, grow and can even suffocate in it's own slime coat.
Reasons for LOW turnover:
Biological filtration ideally needs the water to stay in one place long enough for the bacteria to be able to utilize the ammonia, nitrates, nitrites, phosphate, etc.
So having said that then next question is, How much water flow/turn over do you really need? Personally, I don’t get stuck on numbers to determine if I have enough water movement as simply getting X amount of turnovers doesn’t mean that you have what you need for your tank. It’s more important to ensure that you don’t have any dead spots in the tank, that you have good gas exchange and that your corals will get random, not laminar, water flow. You don’t want to have the water going past your biological filtration areas so fast that the bacteria gets swept away in the currents. Likewise you need to have enough flow around corals to ensure the they get food and that extra slime can be removed from them. You need to ensure that there is a bit of a ripple at the surface of the tank to aid in gas exchange.
So my answer to your question what your exact turnover rate is, is I don’t really think it matters provided you have enough movement to accomplish the above reasons of WHY you need the flow! If you can do this with the pumps that you have, then don’t worry about the exact number of times the water is turned over!
Reasons for HIGH turnover:
One of the most obvious and important reasons for having good water movement in a tank is for gas exchange. Due to the nature of saltwater and the temperature we keep them at it is hard to keep the oxygen levels high for the animals. A build up of CO2 in the system has an extra disadvantage of driving the pH down in the tank and eventually exhausting the alkalinity.
With the large amount of rock generally found in a SW tank, you are faced the problem of debris getting caught up in all the small places in and around the rocks. To prevent this from happening it's important to provide a lot of random water movement in the tank. Ideally, this random water movement will carry the debris away from the rocks and towards an area in the tank where it can be easily removed through vacuuming or using a mechanical filter before the water is further processed.
A lot of harder to keep LPS and SPS coral (and thus reef fish) are found in areas were there is a lot of turbulent water flow coming at them from all directions. Corals have come to rely on this turbulent water movement for a food source and to slough extra slime, decay and debris from their tissue. Without this valuable service then animals will not be able to photosynthesize, grow and can even suffocate in it's own slime coat.
Reasons for LOW turnover:
Biological filtration ideally needs the water to stay in one place long enough for the bacteria to be able to utilize the ammonia, nitrates, nitrites, phosphate, etc.
So having said that then next question is, How much water flow/turn over do you really need? Personally, I don’t get stuck on numbers to determine if I have enough water movement as simply getting X amount of turnovers doesn’t mean that you have what you need for your tank. It’s more important to ensure that you don’t have any dead spots in the tank, that you have good gas exchange and that your corals will get random, not laminar, water flow. You don’t want to have the water going past your biological filtration areas so fast that the bacteria gets swept away in the currents. Likewise you need to have enough flow around corals to ensure the they get food and that extra slime can be removed from them. You need to ensure that there is a bit of a ripple at the surface of the tank to aid in gas exchange.
So my answer to your question what your exact turnover rate is, is I don’t really think it matters provided you have enough movement to accomplish the above reasons of WHY you need the flow! If you can do this with the pumps that you have, then don’t worry about the exact number of times the water is turned over!
