I had posed some questions to a respected authority on copepods. PM me if you want the source. There is some mention of canabalism; although, i'm not really sure it is relevant.
• Your website refers to Nitokra Lacustris – Are there any benefits over the Tisbe for Mandarins?
>>> Tisbe is a better size for Mandarins, Nitokra is quite tiny. Tisbe will grow like crazy in your system as well and be more easily accessible to the fish.
• Would you recommend introducing both species (Tisbe and Nitokra) into our tanks at the same time?
>>> I think Tisbe alone or a combination of Tisbe and Tigriopus might be helpful if you have an adult Mandarin.
• Are either of these species cannibalistic? – In other
words, will they eat each other if another food source is not present?
– Will they prey on the other species? – Will one species dominate in the long run?
>>>> That is a good question. There is some thought that Tigriopus might be. I grow them together regularly without a problem. Tisbe will just do better in the long run because it is more acclimated to tropical conditions, and reproduces faster. It also has a shorter life cycle.
• Is it possible to introduce to many copepods and effectively overload the system? – My research suggests that this is not possible provided they have sufficient food within the system. The more copepods the better?
>>>>> No, the copepods adjust to your systems resources. There is a natural carrying capacity that can't be exceeded if your water is being treated properly. If you suddenly have a lot of algae or bacteria in the system, you might see an increase in the copepod population. This doesn't usually happen in reef tanks. I usually recommend putting in about 1,000 copepods per 50 gallons when you are getting started.
• You mentioned that Isochrysis is sensitive to light and that it is helpful to place the light source 18” from the phytoplankton. I assume this would be somewhat dependant on the wattage of the light source? – The Aqua Medic Plankton reactor uses an 18 watt bulb that extends the full length of the reactor (apq. 2.5 feet / 2.5 liters) – Do you feel that this is too much light? – As the light source is directly attached to the reactor, would a filter be sufficient to reduce the light intensity?
>>>>> I would put some shade cloth between the light and the Isochrysis. Shade cloth can be found at any garden store. I'd start with 50%, maybe grade it down to 20% if growth is not good.
• Any other thoughts?
The most common mistakes I see are overfeeding the copepods and not using the correct screen sizes to collect them. Other than that, they are pretty hardy.
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