What am I doing wrong?

[shluffer]

I have a 55 gallon tank. It seems that every time I add fish (to replace some that pass on) They do great for a while. No signs of stress. after a while (three or four weeks) I have some of them die off. I monitor PH ammonia and nitrate. My nitrates are 10, ammonia is zero, and PH is 8.0. I keep the tank at 76. prior to my last die off, I had 2 gsp (little guys), one figure eight, a mono, and 2 knight gobies. I jsut lost two puffers and a night gobie. I overfed (not good) and had a nitrate spike just prior to the incident. Is that what caused it? I currently have a marineland biowheel type filter. would I be better off switching to a sump type filter?

The only thing I can think of that could be caussing the problem (other than the nitrate spike) is that I am using chiclid salt and buffer instead of marine salt. Could this be the problem?

I am going to hold off adding fish for a while. Having them die depresses me.

 

[Pyramid_Party]

Yep, brackish tanks should use marine salt instead of aquarium/cichlid salt. Also, do you moniter salinity? Maybe there is too much salt or not enough, or perhaps they arent acclimatized right. Alot of times the LFS have these brackish fish in FW. So you must do the job of acclimatizing them to brackish. And you have to do this slowy or they could be shocked.


What were the nitrAte readings?

 

[shluffer]

They jumped to about 40. I don't think that the reading was correct because I changed out 5 gallons and they dropped to about 10. That implies that the reading was really 20. either way I don't think that should kill them.

How do I switch over to marine salt? Should I just do it slowly as I change out water? What salinity should I start at?

 

[Shiroi Katsune]

Ideally you want no ammonia or nitrite, and very little nitrate if any. I use the same size tank as you and run a Magnum 350 and Bio-wheel 330 on mine packed with bio media. I also keep lots of crabs and such to help minimize food waste as well as plants to use up any ammonia, nitrite, or nitrate that may be in the water. This set up works great and I actually show zero for all my levels. As far as the salt goes you definatly need marine salt. Marine salt and aquarium/chiclid salt are two completely different things. Get a good hydro-meter such as Marineland (works great for me) to measure your SG. Brackish can be anywhere between full fresh (1.000) and full salt (1.026-1.027.) Your level will depend on the fish you keep as different fish have different requirements. As far as switching over, do large and frequent water changes in the 40-50% range closly monitoring your SG and adding Marine salt to the new water. This should also help your nitrate readings as you will be removing a great deal of it with the water changes. Be careful of changing the SG too rapidly though, as the benificial bacteria can not handle too large of a change, they must be slowly acclimated. I'm personally a big fan of biological filtration, so I try to get as much of it as I can. If you can kinda make a complete mini eco-system your tank eventually kinda takes care of itself with far less input of your own. I like to look at marine tanks for inspiration.