Backyard Aquaponics
A place to discuss aquaponics

Is a pH of 6 ok to introduce fingerings into? Catfish and bluegill. Thanks!

6... what did you use to test? API test kits only go down to 6, so your real ph could be lower.

That's pretty low to I wouldn't

That, as Ron said, depends on what you are using to measure it with. With a good quality meter, it's a bit on the low side, but with test reagents with a coarse resolution and a lower range limit of 6, I'd be wanting to raise it ASAP.

Yes but SLOWLY.

Rapid pH swings can kill your fish deader than a dead thing.

Many people run their systems at around 6.5pH so 6 isn't incredibly low but if 6 is your lowest measurement then as others have said it could be a lot lower.

I'd start adding a little bit of potassium carbonate or calcium carbonate or an even smaller amount of potassium hydroxide to gradually raise the pH over time. ie a little bit each day.

What and how much is going to depend on how your plants are doing.

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And I notice that perch go of their food at 6, but get it back to 6.5 and the feast is back on..

What do you have available to raise pH... I know it is not ideal, but I use Bicarb-of-soda from the kitchen..

It WILL raise the sodium level in the system, but I am unconvinced about the warnings, WHEN you have already added SALT and you regularly loose water from silly events...

As others have said... get that pH up... add a teaspoon of BiCarb each hour, remeasuring each time, until you get a green colour..

As Gordon said, the only real way of keeping good control, is to use an electronic meter and even a cheap one, will likely be better than reagent testing that just STOP at 6

http://www.aliexpress.com/snapshot/6474934104.html?orderId=65631752032353

This device cost 12.50 and works near as well as a much dearer unit... as good as needed for a quick snapshot of pH
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You have mentioned these warnings a number of times in a number of threads but all I have seen is at most concern over elevating the Na concentration. Do the warnings come from a credible source? Backed up by any research from the Hydro world or any where else for that matter?

Here you go Stuart:

pH Control
Calcium hydroxide
Potassium hydroxide\(Never Baking Soda) (in red)

from
AN ENGINEERS DESIGN AND
CONSTRUCTION DETAILS
FOR SEVERAL CLASSROOM
AQUACULTURE/AQUAPONICS SYSTEMS

James M. Ebeling, Ph.D.
Research Engineer
Aquaculture Systems Technologies, LLC

Michael B. Timmons, Ph.D.
Professor
Dept. of Bio. & Environ. Eng.
Cornell University

Paul G. Hightower
Research Biologist
Aquaculture Systems Technologies, LLC

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Thanks Guna.. But did they explain why...

Is it a preoccupation with sodium that is spliflcated, by the disproportionate addition of SALT..

Indeed, I have no justification for the the warnings and indeed, it was likely Guna' who made the first warning..

I keep talking about it in the hope that someone would come up with a genuine reason

Many an EXPERT warned us to refuse Butter and eat Margarine, and we now know the calible of those experts.
And, then the fools telling us that Saccharin or NutraSweet was better than sugar...

So... can anyone tell us WHY, rather than referencing an unexplained quote... ( no disrespect to anyone) but WHY..

PS... just noticed the size of the FT... a teaspoon will do nothing... and I do again wonder about the foam..

Pps... http://integrated-aq...-2013-04-09.pdf
This is the presentation, I presume... seems to be a power point presentation, with no justification..
And the system... suggested for a school they would have to be joking..
..
.

This is from the site 'Aquaponic Solutions'

I remember when you first mentioned it and I said that I had never heard of anyone using it and "what about the sodium?".

This is an important question whether the Na is coming from NaCl or elsewhere becuase it would help us understand how Na leaves the system or whether it builds up over time. NaCl doesn't seem to and if anything AP systems often seem to "leak" salt because it disappears over time. This is in contrast to HP systems where Cl is one of the major contaminants that needs to be removed from system water.

BuiDoi, it is not so much about adding sodium, as it is about adding an unknown ammount of sodium. If you have a salinity refractometer, you will have a better grasp of how much sodium is in your system before adding more salt. I have used it in a pinch too. I found that it's effect did not last long. I prefer shell grit. Once I added that, things stabilized right out. Salinity refractometrs are relitively inexpensive, so if sodium bicarbonate is your prefered ph reducer, it might be a smart investment.

Thanks for all the info. Over the last 24 hours I've slowly increased the pH to a much better 6.6 with baking soda. Took 28 ounces of it. And the guy at CVS gave me an odd look when I bought five boxes of the stuff.

I do have a reflectometer from my old salt water reef keeping days, so I can keep an eye on the salt as well.

Probably because he knew you can get like a 15 pound bag of the stuff at Costco for the same price of one box there.

Lol.. For sure. At 1.27 per box, this was the smallest expense in my aquaponics adventure so far. I keep thinking I'm done spending, but not yet. :-)