Backyard Aquaponics
A place to discuss aquaponics

I would lay money on the concrete and the hard water creeping the pH up. That's a lot of buffering you are working against. I'd suggest testing pH daily (at the same time of day), and adding small amounts of vinegar every day to try to keep a steadier pH. For example, add 1 quart of vinegar each day rather than 1 gallon every 4th day.

Ouch, poor fishies. Lessons learned though. Any chance of a Noah's Arc for a few?

All perch are dead. I am out of the perch game. They were the least hardy for my problems. Jones really sent me nice perch. I ordered 2-4" and got 4-6". The average weight of 7 perch weighed was 27g - very nice! I feel bad about killing them.

Janet, good advice. I am having my problems. The Hanna pH meter died. I have another meter on order and I am doing test kit with color chart until it arrives. I have had bad luck getting accurate readings with the test kits. A range of 0.4 pH looks much the same in color to me.

I would like to catch a break soon, but I am determined to get things working!

Thats the spirit keep at it Doug.

I feel your pain. I have been there and when you get on the other side it is a great feeling. It sure is dark while you are going through it though.

Don't give up.

Been there done that the only way is back on the horse straight away

Your test kits should be accurate enough for what you need right now. and your alkalinity may not kill many more fish -- it may have been the shock of changing pH as much as anything.

I wonder if it would be possible to make a temporary liner out of 6 mil polyethelene. You might be able to "scoop" it under the fish and then pump the water out from underneath it. Even with a few holes, it would help isolate the fish water from the concrete. In a month or two once the tank has cured, it could be removed in exactly the opposite way -- peel up a corner, pump water between the liner and the tank and then slowly slide it out.

Concrete leaching?
I have never seen signs of leaching on the inside of a tank.
Only the outside, I have to ask what ingredients were used?
I have repaired several hundred concrete rain water tanks
and always the the freelime is pushed to the outside.

Disapointing to kill your fish I too am a mass murderer!

c1, I put a soy based sealer on the inside and I thought that would prevent leaching lime.

Today I found one dead blue gill and one dying perch (he must be the last one). This is much better.

Janet, the pH was over 8.8 this morning. You win your bet. I added 1/2 gallon vinegar and it will take about 6 hours to thoroughly mix. Meanwhile, I will pickup my wife at the airport (back from Greece with lots of pictures/videos/stories to tell).

The fish are eating more vigorously - good sign.

My vegies are taking off - plenty of salad and small zucs & crook necks, cucs are flowering. Time to put up the climbing cords to the ceiling. Pole beans are putting out tendrils. NICE!

FYI i read somewhere something about acetic acid (vinegar) not being the best choice. Something to do with the acetates and a few reactions down the line the PH bouncing back up...................sorry can't link to it, just a vague recolection.

Go sus out a container of pool HCl...........the labels have the analysis most of the time, so you can see what impurity % it has before buying it (regarding NJH's HF warning)

Yeah, pure HCl or HNO3 would be ideal - but as steve says, get the full analysis! Citric acid should also be fine.

a) remember to dilute the acid into the water, stirring all the time - Strong acids get very hot when mixed with water, and adding water to acid can result in sputtering buckets of hot acid...
b) dilute the acid in a separate container of tank water first, then readd when the pH is somewhere you'd be happy to have fish in. (pH 3 is not suitable for fish

Doug, maybe you should take a water sample to a lab that does tests for household drinking water. Last time I had my well water tested I think it only cost around $25.

-Stevo

not sure if the hot thing happens with the HCL. From memory the highest conc. you can get is 33% as its HCL gas dissolved in water, and thats the saturation point. definatly safer than Conc. HNO3

I'm pretty sure that the heat comes from the energy of dilution, so it should happen with all acids. Perhaps HCl just isn't concentrated enough to be a problem. Oleum on the other hand...

WP says 20molar is the highest concentration of HCl.