New fish and Nitrite spike

[Fred]

Hi guys.  After cycling my system for about 6 weeks and completing start-up without fish, I added 15 tilapia fingerlings 4 days ago.  I fed them a few grams of powdered fish food and they eagerly ate it up.  I followed this with several more feedings the next day.  I think I made a mistake here.  Now 4 days in, I've lost 1 fingerling last night.  Water quality seems cloudy and there's a notable fish smell from the system (the fish food is made from fish by product).  I've tried to keep a detailed AP log and I hope someone can suggest my next steps.  My system is 50 gallons with a constant flood and drain using loop siphons and hydroton.  My growbeds are not full yet, my seedlings are still too young.

Should I do any of the following:

Add composting worms

Add a small swirl filter

Continue to not feed the fingerlings

Change water

Add (Buy immediately) more plants to the grow bed

Add more sea salt to help with the Nitrite.

 

[Hal Hurst]

Question: did you add anything to eliminate chloramines in your city water?  I was surprised a couple years ago when I discovered that it is no longer possible to remove chlorine from tap water by just letting it stand a few days, as we always did in the 60's.  That's because most major water utilities are now adding chlorine bound up with ammonia to stop it from coming out.  Your aquarium store will have a chemical, possibly AmQuell, that will detoxify tap water for fish.  But it releases ammonia so that will complicate things until it dissipates.

If chloramines are still present, then nitrobacter will take a hit, or die off completely, so you will have to first detoxify, then add nitrobacter.  That said, a cloudy appearance is normal for a tank that's cycling, but if  chloramine and chlorine levels are low then I would just add nitrobacter and make sure water circulation and oxygenation is ample.  You can get a nitrobacter supplement at an aquarium supply store. My nitrate/ nitrite problems all vanished when I doubled my water circulation. Though I am using a bioflter and not a grow bed, I think the principle should be the same.  I sometimes feel as though I am raising nitrobacter, not fish, and when the bacteria are happy, everyone else is happy.

[Bradly]

Thats a great point Hal....

I bought and use a filter for $50 on line that goes on the end of my hose that removes chlorine and chlorimides if you run the water slowly...at least thats the claim, and I haven't had the cloudiness problem that Fred got.