recycling my system.

[len pierce]

I started my system again after killing all my fish.  I have a total of 180 gals and grow media with expanded clay.  I did have a float system but have taken it out and replacing the liner.  During the recycling now for 5 days I have added ammonia each day and it as been consumed each day.  I have no nitrites that I can measure but after 5 or so days I decided to test for nitrates and found that they were at least 40ppm. Is it possible that the chlorine bath only killed the fish and the bacteria in the grow media survived?  Where would the nitrates be coming from otherwise?  I used irrigation water from the river to start the system this time and avoided tap water.  If in fact the system survived  can I replace the fish?  Do the nitrites come and go so fast that I can measure them?  Questions, questions.  All from a new grower.  Any comments would be great.  Len

[Harold Sukhbir]

Hi Len,

To be sure you can test for Nitrites a few hours after dosing ammonia, every hour, for about 4-6 hours. The next day test after dosing from the 6th hour to the 10th just to be sure. Could be the river water was preloaded with a fair density of bacteria, could be your system is cycled already. Give it a few days and test as suggested, it won't be long before you'll know all the facts.

[len pierce]

Thanks, I added ammonia this am and tested tonight and had no measurable nitrites at a pH of 6.85 at 74degrees but my nitrates are now close to 60 ppm. My ammonia level was 4ppm. I replanted the grow beds and that will help control the nitrates I'm guessing. I plan to watch for another week and then try again with fish when the ammonia levels are below 0.25ppm provided someone has something to suggest that would change my plan . I was going to add liquid seaweed with iron as well but with my nitrates up I am going to wait on that.

[Harold Sukhbir]

Hi Len,

You need to hold the ammonia level at 4ppm, so no more dosing. Yes the plants have enough Nitrates, good for growth. Please continue testing for Ammonia and Nitrites each day from tomorrow. If your ammonia starts to decrease and you still don't get a Nitrite reading I'll have to suspect a faulty test kit. But, at any rate lets just wait and see

[len pierce]

Thanks again for your help? I was not sure how fast the nitrites were changed when things were totally cycled. I will see what happens this next week.

[Vlad Jovanovic]

When you tested the irrigation water before adding it to your system what did the numbers say? Testing your source water before hand is always a good idea so that you have a baseline to work from.

[len pierce]

Vlad,
The pH was 6.9 . I did not test for ammonia or nitrates. Fish grow well in the water as it flows in the river and I confess I thought that was a good criteria for it's use. That doesn't rule out diseases or other heavy metals but a billion dollar a year food industry uses this water supply to grow food and so I trusted the source as I did for years growing tree fruit. It would have been good as you say to have tested for nitrates just as a matter of interest. I think I will now so I can compare. Thanks.

[len pierce]

I just retested the irrigation water and my tank water and found no nitrites or nitrates in the irrigation water. The tank now test 0.25 nitrites and some where around the color on the test chart for 60 ppm. The pH of the irrigation water was 7 after calibrating my pH meter. The tank was pH 6.95. As someone very new to all this, only have taken Silvia's online course, these numbers suggest to me that when I had adequate ammonia in the system for for an adequate time period, the nitrates and nitrites were produced And I only killed fish. Maybe the liner I used along with the chlorine treatment was all I needed th change. I will run this week and then try again with fish. Thanks to all who contributed advice.

[Harold Sukhbir]

Hi Len,

A flowing river ecosystem probably won't show much on the test, but it sure will have bacteria alive in it. You should still be keeping an eye on the Nitrites especially, see if they peak or flatline. My guess is, as you haven't had any nitrite reading previously and are now registering some, it'll probably rise, peak, and subside. But we still have to wait and see

[len pierce]

Thanks for that.  I will watch this week.