Backyard Aquaponics
A place to discuss aquaponics

I have been growing my brassicas in 10 litre buckets filled with pea gravel with some success. The plants are watered by a 6mm tube from a main 19mm tube pumped from the FT. The buckets drain from a hole in the side of the bucket near the bottom and return to the fish tank via the trough the buckets are standing in.

All seemed to be going well until I've noticed that the older leaves are starting to turn a bluish purpley colour which the Yates garden guide suggests a lack of Potassium. I understand banana skins are a source of potassium but is there any other way of adding potassium that will not harm my goldfish?

Eco Rose which if used as a spray can protect against leaf desease as well

Yep as Mantis says, though they have now changed the name of it to "eco-fungicide" with their new stock.

Hi CGD,

If your system pH is low and needs buffering up with lime etc from time to time, then you can use the Eco-rose (Potassium bicarbonate) in the same way as the lime. Simply add it to the water in your system, it will buffer the pH up and add Potassium at the same time.

I would add it at a rate of one well heaped teaspoon per 1000 litres (I've read of people adding more than that, but best to err on the side of caution). Mix the teaspoon of Eco-rose into a bucket of water from your system (or top-up water about to be added), make sure it's thoroughly dissolved, then add to your system by pouring a 1/4 of the bucket of water into your system with each bell siphon cycle, or every 15 minutes or so in a timed or CF system. Check the system pH a few hours later, and if you still need to raise the pH further then use lime as per your usual method.

Don't use it each time you buffer your pH up, you can have too much Potassium, only add when your plants show signs of needing it, or maybe every couple of months as a precaution if you are growing fruiting/flowering plants

I added some to my little AP system a few days ago for the first time ever and I can see a difference in the plants already, especially my Capsicum seedling and Asian greens seedlings. I have two varieties of lettuce, one variety has gotten noticeably greener in only a few days.

Cheers.

Cream or tartar

Has anyone tried palm ash. Its sold as an organic fertilizer (0 - 0- 30). http://www.planetnatural.com/site/organic-potash.html

Are there any problems associated with adding banana skins to a GB for potassium?
Your OP suggested it might harm the Goldies, or did I just read it wrong?

Hi phivtoosyx,

I googled Palm ash and found the following points of interest.


In aquaponics it's advisable to avoid the addition of copper to the system, for the sake of the fish.


From my own personal POV, I wouldn't use any products knowingly derived from the production of Oil palms.
Oil palm production is causing widespread environmental degradation in SE Asia... and only a few days ago it was reported that 30+ Orangutans were killed by workers from one plantation alone.

Not preaching, but here is a link to an article that covers both the animal cruelty and negative environmental aspects of Oil palm production: http://www.cosmosmagazine.com/news/1496/palm-oil-workers-killing-orangutans



Hi DuiNui,

I'm not sure if your question was a general one for the forum, or whether it was aimed at phivtoosyx asking if he had an issue with adding banana skins to his system as an alternative to the Palm ash.

If it was a general question for the forum, I can tell you that I haven't had any isuues with adding Banana skins to my systems. I bury the skins in my gravel at the high water level. You will need to add some composting worms to your GB before adding any banana skins, otherwise they may just rot and turn to goop in your GB.

Cheers.

CGD said in the OP "I understand banana skins are a source of potassium but is there any other way of adding potassium that will not harm my goldfish"
Which implied that adding skins might harm the goldies.
I added them to my previous system and it didn't seem to make the problems I had any worse, hehe.
Thanks for the reply

Ahhh... OP... Opening Post... Doh!!!... I'm with you now!

"Sodium-free" water softener, aka Potassium Chloride...

How does Potassium Chloride... "softened" your water...

The same way sodium chloride does. How it works is besides the point. The sodium free water softener bags (at least here in the US) are made of potassium chloride. 50lbs for about $20.

From Wikipedia... but you can find the same information in numerous other sites.

Regeneration

The resin's capacity is gradually exhausted and eventually it contains only divalent ions, Mg2+ and Ca2+ for cation exchange resins, and SO42- for anion exchange resins. At this stage, the resin must be regenerated. If a cationic resin is used (to remove calcium and magnesium ions) then regeneration is usually effected by passing a concentrated brine, usually of sodium chloride or potassium chloride, or hydrochloric acid solution through them. For anionic resins, regeneration typically uses a solution of sodium hydroxide (lye) or potassium hydroxide. The salts used for regeneration are released into the soil or sewer.

Here's more from Morton's site:
http://www.mortonsalt.com/faqs/water_soft_faq.html#q22

Unless this is an issue of both of us speaking english but the words meaning different things to us. Water softener is a misnomer, because it doesn't soften the water, it's just what we use in vernacular here in the US referring to sodium chloride or potassium chloride when used for the water softening system.

If it's a 'meaning' issue, I also might be mistaken where the confusion is? The 'soften' part maybe?

No disrespect to those that sat at the front during science class, but... CAN SOMEONE EMAIL ME PANADOL?... MY HEAD HURTS!!!

In english please... Is it fish and plant friendly?... and what will it do to the pH?

I know about the individual benefits of Potassium to plants and Chloride to the fish... but will this be okay in an AP system?

Cheers!