View Full Version : dealing with Nitrates in a brackish aquarium

01/02/2013, 07:36 AM
i have been keeping a brackish (salinity 13) 55 gal aquairum for a couple years. i keep chesapeake species native to my area; typically for a few weeks at a time and have some long-term minnow residents. the tank has been going for a couple years with very modest partial water changes.

as background, i kept marine fish-only tanks for several years and have been keeping freshwater for about 20 years through various geographic moves etc.

i had no idea the nitrate problem i am now facing for quite awhile. it was noticeable that an adult yellow perch or pickerel placed in the aquarium would begin getting cloudy eyes and having health issues within 1 or 2 days requiring release before becoming worse. i tested ph and it seemed ok. about 7.5 i think.

i finally tested nitrates and found them to be basically off the scale. 5 gals at a time, i changed 50% water in a few days, but still tested at the highest end of measurement and finally tested my tap water which comes from well and found it was very high in nitrates, possibly outside of EPA limits depending on how accurate my testing is. we drink bottled water and i do not see the tap water being a problem for me personally but this seems to confound my aquarium nitrate problems.

currently, my aquarium has undergravel filtration, mostly to allow me to have a thick covering of relatively large diameter pea gravel for aesthetic reasons. it also has a fluval cannister filter.

can anyone recommend proper filtration equipment and maintenace program for my situation?

i am not sure if protein skimming is even an option for brackish water.

my goal is to resolve the nitrate issues now, and then bump up to a 90 gallon tank and keep a couple of larger native species long term. the yellow perch would be nice as they are active, but not crazy. the white perch seem hardier and are good too, but not as attractive as yellow perch.

thanks ahead of time for your consideration and any help you can provide or point me to!!