bluegill fingerlings in my first time setup are kicking off

[Stalemate]

My wife picked up 40 bluegill fingerlings and 4 catfish on friday to add to our first setup which we just finished cycling.  9 of them died on the way home, and 5 a day for the next two days.    The ph is reading 7, no amonia signs and water temp is 71 degrees.  Also,  a few fish are showing discolored regions on their back and tailfin.

Is this mortality rate in a stressful move usual? Should I be investigating / worrying about an underlying problem that may kill them all?  When I visit them, they seem happy. They are usually grouped on the  sunlight side of the tank and eat small coy & goldfish pellets that i'm crushing for them

[TCLynx]

I would recommend looking into solar water heating as that is going to be more efficient that generating solar electricity and then using that to heat the water.

On a side note though, if your layout isn't really designed to use a thermosiphon, you might use PV panels to run a small pump to do the recirculating of water through the solar water heating panels since then you get the benefit of the PV panels only providing power to run the pump when there is sun enough to hopefully heat the water heating panels.

[Aquamaple]

Thank you for posting this excellent thread Stalemate, and thank you Jon Parr and TCLynx for the great information! I was worried sick I was going to lose ALL of my hybrid bluegill. I may yet, but at least I have something to try in the mean time, and I know how to do things different if I have to start over with all new fish. This has seriously been a GREAT find for me.
 
Jon Parr said:

Get course rock salt from Orchard supply, or similar, it's only $5 for 50 lbs. Aquarium salt is the same thing for 100 times more money. My advice, especially for bluegill, is to dose at 5 ppt. This isn't prevention now, this is a visible full-on infection. Salt at 5 ppt won't hurt your fish, or your biofilter, and it wont change hardness or pH, but it will slow or stop growth of many plants. So if your plants are too valueble to endanger, disconnect the growbed from the loop, and hand water during treatment. I would keep it salted for 2-3 weeks, and then do daily water changes until your salt is below 1 ppt before rehooking the growbeds. If the plants are no big deal, keep the growbeds cycling.

[Tradewind]

About tank heaters.  Though I have yet to put one to use, I saw that our local Tractor Supply Company has stock tank and bucket heaters.  It appears that these would work well enough.  I am not sure about temp control as they may be used just to prevent freezing but it is something that offer an option.  Pricing is certainly acceptable.

[TCLynx]

Just make sure that the stock tank or bucket heater is stainless steel before using it as a fish tank heater.  There are stock tank heaters out there with thermostat control as well as being stainless steel and if you find one made from an acceptable material but it doesn't have a thermostat, you can buy a separate thermostat with a temp probe that you can plug the heater into.

[Tradewind]

TCLynx said:

Just make sure that the stock tank or bucket heater is stainless steel before using it as a fish tank heater.  There are stock tank heaters out there with thermostat control as well as being stainless steel and if you find one made from an acceptable material but it doesn't have a thermostat, you can buy a separate thermostat with a temp probe that you can plug the heater into.

Now that you mention stainless, I recall that I made a heater with a stainless element I bought at Lowes.  In fact, I still have that element but I took the heater apart.  It was made using PVC.  I got the idea from a you tube video that showed how it was made.  It was kind of interesting actually, but for some reason I put it aside.  I might have been thinking the blue gill could probably handle our climate in SE Texas. My tank heats up pretty well if I leave it uncovered in the sun, so maybe all would be well.  Unless of course, we got one of those rare ice storms, then all beats would be off.

[TCLynx]

I found that bluegill and channel catfish can handle heat and they can handle cold.  What they can't handle is temperature swings that are too extreme too fast.

[Tradewind]

That is one thing about Texas, you don't have much temperature swings, when it gets hot it just stays hot.  I was actually thinking about a chiller, but as you said bluegill and channel cat can handle the heat.  I believe that Hybrid Striped Bass can as well, maybe even better than the two aforementioned.  Right now I am running with Shiners.  The guy that sold them to me has a tank he keeps at about 65 degs and told me that once they got past 70 degs they would be dead in an hour.  So he says, but it is just not so.  I think maybe his dissolved oxygen is so low that when it heats up they just drown.  My little guys seem to love my water.

TCLynx said:

I found that bluegill and channel catfish can handle heat and they can handle cold.  What they can't handle is temperature swings that are too extreme too fast.

[TCLynx]

Well, systems in bait shops are often stocked to the point that if they were not using chemicals to lock up the ammonia, the fish would be dead very quickly and if their aeration failed or the temperature were to rise to a reasonable living temperature for the fish, they would all consume the dissolved oxygen so quickly yea, I expect they would be dead in less than an hour.

That is the problem with packing lots of fish into a small space and also why buying fish from a bait shop often sticks you with fish that might be in bad shape to begin with and may not survive well if they were in the bait shop tank for very long.  Bait shop fish are meant to be Bait for bigger fish very shortly after they are purchased so the point isn't to have fish that will survive long therm.  (Kinda like buying feeder goldfish, they are often not long for this world.)

Now doesn't Texas get some wide temperature swings in the winter?  Which part of TX are you in, Dry or Gulf Coast?  Here in FL it doesn't cool off much at night once the wet part of summer starts so there is little chance of using evaporative cooling at all and the radiant chilling doesn't work as much on cloudy humid warm nights.  In the winter here though we can go from a hot day to a freeze night with minimal transition time in between and having a fish tank go from 64 F to 34 F overnight is TOO fast a temp swing for most any fish to LIKE.  This is why I recommend 300 gallon + fish tanks for outdoor non temperature controlled systems here and please limit the amount of towers or NFT growing to avoid swinging the temperatures much more than 10 F between day and night if possible.

Now if your water temperature is over 90 F then you may need to take some extra measures to cool things off but 80-86 F is actually a great temperature for growing out many warm water fish types.  If you choose a native warm water North American fish, most of them will survive freezing or nearly freezing water for a time in winter as well.

I've actually always thought Bass liked it a little cooler than the catfish and bluegill but I've never really researched it, bass are not actually that great an eating fish according to many people I know (Like my Uncle who is "Goofy about Fishing", his book title.)  Bluegill are good eating though small.  Catfish are actually really good eating though many people have objections to them because they don't have scales and because they are supposedly bottom feeders, the first means they are a bit more sensitive to handling and poor water quality and the second is a moot point in aquaponics.