Backyard Aquaponics
A place to discuss aquaponics

I need to raise the pH cause its sitting at 6 ( according to the test kit , it might even be lower )
plants are not growing much , seedlings are going slow

the fish dont seem to mind so Im assuming the pH isnt TOO low

I also need to add Potassium to help the tomatos

so Ive bought :

1 bag of Dolomite Lime
14% Calcium Carbonate
8%Magnesium carbonate
70% neutralising value ( what ? )

the msds says it is NOT soluble in water though ....
pH is listed as 10 , so that will do the job nicely if it does dissolve

theres no potassium in it , so I also bought : Dutchfest Hydrogrow part A ( concentrated nutrient for hydroponics )

Total Nitrogen 2.9%
(of which only 0.1% is ammonia , the rest is Nitrate )
Potassium as Potassium Carbonate 6.0% ( thats what I want )
Calcium 3.5%
then negligable amounts of Chelates of copper , iron , manganese , zinc , borax and sodium molybdate

any glaringly obvious reasons why I shouldnt add small amounts of either of these 2 things to my system ?

You could just buy a packet of EcoRose (Bunnings)... Potassium BiCarbonate...

High Potassium.... and a strong BiCarbonate buffer....

That and a packet of Chelated Iron... and/or some Seasol... is all you'd need...

Ive got chelated iron , but the seasol Ive got is powerfeed , with fish guts in it ..

I went to grab a packet of ecorose but on the back it says poisonous and to not let it get into streams and waterways , so I bought what I bought

I know nothing about either of those products but I put 4kg of garden lime, which is just crushed natural limestone, into my 4,500L FT and the pH went from 7 to 8.

I was told to do this by the guy who runs the Gigie SP fish farm as he said it buffered overnight pH changes in a tank with algae and added numerous trace mineral to the water which help the Silver perch.

The SP fingerlings were in the tank at the time and I supidly just droped the whole 4kg in at once. The water goes very cloudy but it did clear eventually and none of the fish died. My pH has never been under 7.4 since so it mcould be a very good buffer, but then again my fish are very small and probably would noit change the pH much anyway.

I may have just got lucky so proceeded with caution.

Trust me... the EcoRose is an organically certified "fish safe" product... the "don't release into waterways" labelling ... is a standard on almost any packaging these days...

The 70% neutralising value has to do with the amount taken to neutralise a known strength HCl.
I'd be abit wary bout the pH of the hydroponic stuff and not using too much either.
The dolomite lime deffinetly won't be soluble in water. Its like adding a chunk of limestone to your system, it'll be dissolved eventually and act as a buffer, but only in acidic water.

ah good , my waters acidic ( possibly lower than 6 ) , how long will it take for the Dolomite to dissolve ?

Ive added a capful off the hydroponic stuff & I'll wait for a while and see what happens

Another, cheap, quick way to adjust you pH back... and I've mentioned it before...

Is "slaked" or "hydrated" lime.... Calcium Hydroxide.... brickies use it.... you can get it anywhere in 20kg bags for next to nothing....

I'd be a bit wary about the "concentrated" hydroponics mix...

Watch out for some Hydroponic products. The canna ones contain pharmaceutical grade potassium not the regular grade. And they recomend using it for only a short period of time then removing it from the plants via water change.

Yep.... if every one needs... or thinks they might need to add anything to their system...

Post it up on the forum.... members over the past few years have pretty much worked/found out what's safe and not..... and what's the best way to deal with any problem...

i have been adding pottassium bicarb powder to my system to raise the ph, so far I have added over half a kilo, @ 2 - 3 tablespoons a day, and the ph is now in the mid six's. It must have been super low lol. I wouldn't add any hydro concentrates when other products are availble that we know are fine. eg the hydrated lime or the ecorose. The potassium bicarb is from the winemakers shops, also from rural supplies where they sell stuff to grape growers etc.

How much affect does Ecorose have on PH? For 5000L tank how much would you need to add to raise from 6 to 7 ?

The finer the dolomite is ground the faster it it will dissolve. I believe it buffers to about 8.0, so anything under that will gradually eat it away. It is slow, so not good for dropping things fast, but that may be unwise anyway. I really can't give specific rates and numbers, but it takes a surprising amt of gravel to keep the system from dropping in the future: somewhere in the range of 10% to 50% of your gravel. I would check TCLynx's system: she has about half shell (analogous to dolomite) and is pretty stable at a good PH.

yea, my shells buffer the pH pretty good but my Quarantine system has settled to a lower pH than I would have expected. It has been hanging around 7 for a while now.

Big system has been 7.2-7.4 for a while.

I would also advise against using the hydroponic nutrients.
The Lime added slowly to the system should help with the pH and buffering. And regular Seasol or Potassium Chloride could take care of the potassium deficiency if you don't want to get the eco-rose or Potassium-bicarb

ok , EcoRose it is - just bought a container

1 tablespoon spread between 2 tanks and the sump , I'll see what effect that has on the pH in a few hours

the dolomite seems to have done nothing for me ( on the other hand , the Movie "Dolomite" did alot for me , it was unintentionally hilarious )

the Dutchfest hydrogrow seems to have done nothing , but its possible that the nutrients in it are locked out because of the low pH ( I really have no idea what the pH is - it reads as 6 cause thats as low as the test kit goes )

Its also possible that Im impatient , but 4 of the fish arent going to get to hang around to see the results of all this adding of stuff - they''ll be in the smoker in 5 hours ....