14 replies to this topic

[danotaylor]

g'day AP crew...

I have found a source of HDPE barrels that have stored nitric acid for transport. Nitric acid is water soluble and I have read on Murray Hallams site that it can be used to gradually reduce ph in an AP system. Logically this means that if used correctly it is not toxic to fish or plants. The chemical engineer of the company selling the barrels says that HDPE does not hold any residual from chemical stored in it but I would like a few other opinions from anyone with relevant knowledge of this chemical or this product (HDPE).

My question is then can these barrels be safely used as growing beds to create a DIY AP system?

Thanks for your time and wisdom.

Danny

[Buccal]

Left out to bone dry in the sun should neutralize most things like that to a degree. Good old radiation.

[werdna]

Dont put too much faith in Murray Hallam. Especially stocking ratios.

You should be right with them.
Give them a good rinse, nitric acid is very soluble, and incredibly fun for reasons not to be mentioned...

The high ph level of our water should neutralise anything remaining pretty quick.
Add tap water and leave for a week.
If ph is stable the acid wont be leaching out, if it drops over the week you might want to add limestone or something to try to react with it to neutralise it.

[ice]

High density polyethylene wont leach anything out into the water as it is impervious to most things (even acids) from ever soaking or eating into it in the first place. Like Andrew says just give it a rinse out and you should be all good to go Dano. Good to see you back buddy!

[danotaylor]

Thanks Buccal, Andrew and Dave...happy to go ahead now...asked Murray H on his blog and he gave the thumbs up too.

Andrew if you read this again what has been your experience as far as stocking ratio's goes? I was think to just keep testing the water once the system is mature and either decreasing fish or increasing plants to keep nitrates stable around 40ppm. Probably a little too complex. Your thoughts?

Cheers,

Danny

[werdna]

Stocking ratio depends more on filtration than tank size. Same as with fish tanks, you cant put ten 30cm fish in an 8ft without adequate filtration.

The general rule is 25 fish per 500L of growbed/filter media. This will allow fish to reach around the 750 gram mark without over stocking the system.
Obviously you would start removing the bigger ones early, but you need to allow for their adult weight.

Remember you will need to add air as well. I lost all my trout when I had power out for 6 hours due to low DO

[bigjohnnofish]

nitric acid is very soluble, and incredibly fun for reasons not to be mentioned...

cmon...... do tell ???

[danotaylor]

thanks andrew...I appreciate your wise input mate...bless ya. dano

[tranced]

cmon...... do tell ???

probably something like this... 2 (NH2)2CO + 2 HNO3 + H2SO4 -> 2 N2O + 2 CO2 + (NH4)2SO4 + 2 H2O

most fun thing that i could come up with anyway...

Edited by tranced, 30 August 2012 - 06:08 PM.

[garlic shrimp]

hey you can give a company in caningvale a call ,Silverlock,they do the 205ltr blue barrels new,look up their number.
they do all sorts of plastic moulded buckets barrels etc.
cheers,
Con.

[danotaylor]

Thanks Con. The ones I have found are $10 a barrel. Since hdpe will not hold residual chemical us the fact that it can be used safely to drop ph in aquaponics it is much more economical to go with the used ones. Thanks for the info though bro. I appreciate your reply

[garlic shrimp]

no probs at all.

[bigjohnnofish]

probably something like this... 2 (NH2)2CO + 2 HNO3 + H2SO4 -> 2 N2O + 2 CO2 + (NH4)2SO4 + 2 H2O

most fun thing that i could come up with anyway...

nitrous oxide can be useful - but how do you collect that and not the carbondioxide... whats with the ammonium sulphate ??? and i dont need the water !!!! lol...

good to see you can balance your chemical equations... see you are useful for something

[werdna]

most fun thing that i could come up with anyway...

Not even close. Try harder

[tranced]

well its great for hydroponics... but who knows what you guys get up to tho

edit: explosives, eh

Edited by tranced, 02 September 2012 - 10:05 AM.