I'll get to the challenges many schools are facing in a minute, but first I wanted to show you the cool video that Seth Bonnett, of Manchester Elementary and Middle School, shot underwater using a GoPro camera. Nice job, Seth!
The second video is of the trout at the Dorset School. If you look carefully, you can see some dead or dying trout in one of the corners of the breeder basket.
The third video, from Jason Gragen, is of the trout at NewBrook School. That's followed by a photo of Jason's students feeding their fish.
Now that the fish in most Vermont TIC tanks are feeding (and urinating and pooping), water chemistry levels have become a serious concern. Here are a couple of recent reports from teachers.
Jason Gragen, NewBrook School:
We left for the weekend with water numbers looking good for ph, ammonia, nitrite, and nitrate. I ran the tests this morning (3/14/16), and we are at elevated levels of nitrite at 1 ppm, and ammonia at 0.50 ppm. This is the first test this year that we've run purple for the nitrite.
Out of curiosity I started investigating. I had found one fish stuck against the backside of the filter intake's mesh, and decomposing. It wasn't visible looking down through the top of the tank because our filter is snug against the glass. So, I'm guessing that it must have been there for a few days or more.
I don't believe that we've been overfeeding at a couple times a day. I've been following the TIC binder suggestions for water maintenance. I performed a water change, and gave the rocks at the bottom of the tank a good vacuum. I pulled up a lot of waste from the bottom, as I have on previous times as well.
Lisa Marks, Ludlow Elementary School:
We had a casualty. There are 15 other fish that look skinny and I have noticed they haven't been feeding which was the same for the one we lost. Is this normal to have a few fish that just never really ate. They seem to be mostly in one breeder basket.
Since one of our breeder baskets doesn't have as many fish as the other three can I combine the fish into another breeder basket that doesn't have as many? I wasn't sure if they would be territorial as far as the mix of the fish into new baskets. I'm still hesitant to drop them into the tank. It just seems so big!
This morning Lisa reported:
We have about 15 fry that are laying at the bottom of the basket and they are definitely not feeding. There are three in that basket which we move from the other baskets that are now swimming up since they aren't competing with the larger fish. Those on the bottom are very skinny, have a silver color to them and only wiggle if you move them gently with the pipette I use to clean the baskets. Could they contaminate the tank and should we dispose of them?
Yesterday TIC coordinator for Central Vermont TU Bob Wible reported:
My Eden tank is down to 30 fish. Still not feeding. They had a situation where the janitor added tap water without treating it. Also, I believe they missed "swim-up." Maybe they will start feeding soon.
Dawn Adams, at Rutland High School, wrote this today:
The ammonia levels in the tank have been around 2ppm for a week. We did a 7 gallon water change and sucked the gravel on Monday. We will perform another water change tomorrow. It seems the alevin are "groggy" in the morning by hanging around in the gravel. By mid day they swim up to the top but not all. Question one: Is this normal or this an affect from the high ammonia levels? It seems as if the tank is not cycling because the nitrite and nitrate levels still remain at 0 ppm.
We've been adding 15 mL of Nite-out once a week (after week 5) along with 10 mL of Special Blend. We have 130 mL of special blend but are running low on Nite Out. My second question: Should we be adding 15 mL of Nite Out twice a week per water change for the remaining time we are raising the trout?
So what's going on?
I think two things.
It's very common for some alevin not to learn how to eat. I'm not sure why that is, but it seems to happen in all tanks to some degree. The case of the Eden School, where perhaps none of the alevin will feed, is extreme. But teachers and their students shouldn't feel bad if they lose some of their fish at this stage. You will have to remove them because, if they die and decay, their decomposition will cause water chemistry problems.
2. Water chemistry changes related to the nitrogen cycle
Your ammonia and nitrite levels have to rise. Normally ammonia increases; then nitrite goes up (which usually lowers your ammonia); then nitrate goes up (and nitrite goes down).
Maryland's Chuck Dinkel knows more about this stuff than anybody I know. Here's his advice:
Hi all, At the recent (Maryland) TIC Workshop, Douglas Dent, of Ecological Labs Inc., manufacturer of Special Blend and NiteOut II bacterial additives, presented a Power Point discussing the topic of maintaining our tanks. A significant recommendation from that presentation is that we double the amount of the two bacterial solutions to help compensate for the slower reproduction rates of the bacteria at the 52-54 degree temperatures at which we keep the tanks.
One of the most important points that I learned from Doug's talk is, in my own words, the following: The bacteria in your tank should provide the first line of defense against changes in your tank that effect water chemistry balance. Water changes are secondary to biological activity. Allowing the bacteria to do their job will reduce your need for water changes. The log of daily water testing and the overall health of the trout will also help you determine how much water to change and when to do so. This is a very important change regarding the approach we previously took to tank maintenance. What it means is that there may be times when, for example, ammonia levels start to increase that the action required will be to add more NiteOut II to the tank rather than increasing the size and frequency of water changes.
Joe Mark, Lead Facilitator, Vermont Trout in the Classroom
In June 2012, I retired after 40 years in higher education, having spent the last 32 years of my career as dean at Castleton. One of the first things I volunteered to do in retirement was to work with Jim Mirenda to help the Dorset School, where his kids and my Vermont grandkids attend, start a TIC program. Gradually that commitment grew into my current role, which is both demanding and highly rewarding.