Backyard Aquaponics
A place to discuss aquaponics

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More than once, I have been told to NOT use Bicarb-of-Soda from the kitchen to raise AP pH, but many of the commercial aquarium products, use just that.. ( but they don't grow plants)

I would assume that it is the Sodium that concerns some, but as discussed many times, if you salt your AP system, then my assumption is that salt will completely swamp the effect of Sodium-Bicarb..

Can anyone tell me WHY we should not use Sodium-BiCarbonate, when we add salt to good effect, and even if we don't use salt, then how is the BiCarb an issue, when our pkants grow well with salt water..

I know there are better products for the task.. I just want to hear a valid reason why not Bicarb..
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You answered your own question. Too much salt, and if you're using it constantly, you'll end up with salt build up and plants will suffer. You can use it in aquaculture, it's not the fish that are the problem, it's the plants.

I wonder how many of the chemicals that are advised no to use are of actual study or experimentation, or just hearsay.

Like seasol powerfeed, reading up on the posts, it's said not to use it because of a build up of heavy metals, but I used it quite happily whenever I had a bit of a nut deficiencies, and it clears it up very quickly without needing to figure out what sort it was.

Or the different types of iron, bright agrotech says it's poisonous, but I've never had any problems.

Colum, what types of iron are poisonous? I've only heard of assimilation issues regarding PH. Baking soda has a lot of salt. I suppose you could use it and find out if it really does injure or kill your plants, but why? When multiple reputable sources tell me something, I usually just follow their advice. I don't need to reinvent the wheel.

http://brightagrotech.com/iron-in-aquaponics/

It's the EDTA type, but the only type that's easy to get locally from bunnings, and several other members on here use it as well. They said not to use it because it's a broadleaf herbicide, and the PH range is bad. But it worked quite well when my PH was around 8, and there aren't any iron problems in my system.

Your assumption is wrong. "Salting" an AP system would typically only be done once. If you used sodium bicarb you would be adding it on a regular basis and the salt would build up.

Plus, domestic grade bicarb may well have anti caking agents if it's the kitchen variety. You salt generally for the cl component not the Na. You could salt with KCl you would then get benefit from the K component with none of the Na disadvantage.

Plants use lots of Ca, Mg, and K why add Na, which isn't really required in any great quantity. Plus it kills plants if you keep adding it.

Sodium, just say No!

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Thanks for the thoughts, and again, i am fully accepting that potassium and calcium carbonates will be better for the plants..

So as it stands, there has been no good reason why Sodium-Bi-Carb MUST not be used or cannot be used,
but long term usage is discouraged..

There is a school of thought that suggests running a system with 3part salt is good for the fish and whilst some plants will cope, others will flounder ..
Then the school that suggests you use 3part as a weapon to fight a specific issue/disease...

So the suggestion is that adding BiCarb is not desirable, because it will increase the salt level, but with salt, you can measure that value, and thus accurately show the impact of adding extra sodium..

The issue of anti-caking is a different issue...



The ALDI product that I inspected did not list ANY anti-caking, but strangely declared. ".... may contain Soy, Milk, Gluten and and.." pure legal disclaimer..
none of the products I found on the web, listed anti-caking agents..

So.. as it stands.. (to me) SodiumBicarbonate remains and non-ideal material but a useable one, provided usage carries the caveat about salt increase...

Anyone got an accurate salinity device and able to measure change wrt a TS of bicarb.
( I have a brix device but got an entirely wrong scale, and unsuitable for salinity)
Take 1L of FT water.. measure Salinity.. add say 5g of Sodium Bicarb... leave overnight and measure again..
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If I recall there is a conversion from brix to salinity for refractometers out there. You got my take on the issue. If you can measure salinity, go for it. That being said, cheap old shell grit works wonders for me.

Nope. Its not desirable because it raises the Sodium level. Sodium will build up in the system as it is not used by plants and have no benefit to the system and will only be able to be removed by water changes. Its the Chlouride component of salt that is beneficial for fish health, BiCarb has no Chlouride ions present. But the pool salt we use in our systems has about 40% Sodium (NaCl) so it is also adding Sodium when we dose. BiCarb can be used to raise pH but its only the Carbonate that is useful, and only useful until it is exhausted by system acidity. There are better options.



1ppt for general fish health and to reduce effects of nitrite.
3ppt for parasite infection
6ppt for fungal/bacterial problems

Not to nitpick but some plants do uptake sodium, notably C4 plants which fix carbon like maize and cabbage. Some plants will uptake it instead of potassium which competes with it. Since most of us have issues with potassium already, you would probably not want to add more to this mix over the salt that is added for fish health.

The true issue as some have already noted is that it increases sodium in the water which can build up to harmful levels over time. I do own a digital salinity measure and I can check on how much it puts into the water in ppt if there is interest.

Sorry I should have said 'not used up' by plants, as in - it will stay in the system because the overall uptake is very minimal. Its harmful to most plants.

Even if we did a ppt measurement after dosage it would not provide any useful information.

BuiDui - if you want to know the change in NaCl salinity - download the free hydro buddy calc and do the calculation in that.

Any Refactometer will respond to other salts in solution (such as KCl), so it does not exclusively measure just NaCl salt levels. I've salted system to 3ppt, and measured a year later and the level has not changed, EVEN with my celery being very salty to taste over that time.

Yes good points... I salted to 3parts and have no doubt it is way down on that, after various overflows and the likes.. ( and the plant growth improvements )

Sorry to be a pain, but I have just wondered WHY the claims have been made and IF they are backed up with measurement..

We have just cause to question the value of Sodium in our systems, but sodium has existed in nature since Adam was a boy..

Not too many of us have Mass-Spectrometers to test our waters to see if the theory is matched with practice..

Again don't get me wrong.. I have no doubt that a Potassium or Calcium carbonate or hydroxides is more "beneficial"
but I am not interested in beneficial, I am thinking "Harmful" or rather How-Harmful..



and even on the dangers of Na, there is differing opinions.. BUT
we clearly see what TOO MUCH will do, as evidenced after a tidal wave etc. destroying fertile lands..


other than understanding at what point, Na levels start to cause problems


I am just questioning the oft hand-me-down comments, quoted and re-quoted until they become scientific fact..
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