Backyard Aquaponics
A place to discuss aquaponics

I bought some "Aquarium Salt' to raise the hardness of my water. It is "jungle Aquarium Salt". On the label it says "NOT FOR USE ON FOOD FISH". Why on earth would it say that?

I know steves opinion on "aquarium salt", and based on http://www.backyardaquaponics.com/forum/viewtopic.php?f=11&t=586%20the%20water%20hardness%20and%20fish%20health thingo, I can just use a source of calcium or (and?) magnesium.

SO. Do I take the Aquarium Salt "NOT FOR USE ON FOOD FISH" back and whack in some shells and a few drops of HCl? Or should I just whack in the Aquarium salt and see what happens?

It's probably just a disclaimer so they don't have to be approved by health inspectors. There's a chance of nasties being in there, but I would think if there was your fish would die. If these are aquarium fish, then 'whoops' if these are eating fish and ppl eat the affected fish, then much bigger whoops. However this is just an opinion and I am not recommending either way

i think much along the lines of KP.

HA, how shifty am I? look up msds's of the aquarium salt and get the ingredients and percentages

http://cms.marsfishcare.com/files/msds/ ... t_2445.pdf 100% table salt

http://cms.marsfishcare.com/files/msds/ ... t_2446.pdf

8.4% calcium chloride
6.2% magnesium chloride
1.9% salt
remainder water (is a solution)

this one above will raise GH

pool salt is very cheap, $6 for 25kg. It would last smaller systems for years.

Jaymie, pool salt wont raise GH

oh, alright

There are other ways to raise the hardness though. Depending on system size the aquarium salt could get really $$

Yeh, using garden lime and a sufficiently low pH should do it. I was going to just mix garden lime, water and hydrochloric acid together, should end up a neutral solution with a high GH (dolomite lime has magnesium in it too).

EEk, be careful mixing such things!

Is there a particular reason you are trying to make really hard water?

I could be wrong but I was thinking a little shell grit added to the sump and perhaps some epsom salts might work too?

lol, you're always one post ahead of me!

i was going to suggest using epsom salts too, it would also give the system some more sulfer and magnesium and is relatively cheap from the supermarket

epsom salts eh?
Sounds interesting.

I need to up water hardness as my tank water measures about 30.... apparently gold fish & trout like it up around 150. The problem with just using shell grit is that it requires the pH to be low enough to actually break it down, but I don't have a low pH. I know it goes down over time, but I need to up the hardness now.

Epsom salts is an interesting idea - magnesium sulphate.

You know I'm just going to use the aquarium salt for now. I can afford to pay $30 more than I should..... =(

Our tap water here comes from a limestone bore and so the carbonate hardness (KH) is 300ppm (very high!). The pH of my system has remained at 8.0 and hasn't shown any sign of coming down.
Can anyone tell me- at this KH will the pH ever get down to 7.0? (which is better for the plants) or is the buffering capacity too great?
I've tried acetic acid and have got the pH down to 7.5, but it quickly returns to 8. Any ideas? Is the only option to mix with rainwater to reduce the KH

adam,
How long has your system been running? I don't know what the KH of my well water is but the guy at the aquarium place seemed to think the water around here would never need any extra buffering because it does come from limestone Aquifers. The pH of my well water after outgasing is 8. (I do doubt that my KH is anywhere near that high) but upon being cycled the pH, in the Barrel system before I had any shells, dropped suddenly. Perhaps with the extreme hardness, you will want to mix with rain water. Other option might be to soften the water but that always seems so wasteful to me and you need to be very careful the type of sofiner system and salt used.

Gemmell,
Next time (since you are using the aquarium salt this time) maybe you could mix some vinegar and water to soak the shells and release calcium, then add into the system once the pH is right.

Good idea. I'll try that out. For now I've got 5kg of water hardner though =)