11 replies to this topic

[Tricoti]

Hi everyone.
I have just ran out of my African KH + potassium powder that I buy which isn't cheep. Depending on which shop I go to it is priced at $150- $175 for 5kg. Having 4 large tanks (8ft, 2x7ft and 6ft) I go through it quite quickly.

My question is:= What do you use to elevate your KH? Do you buy it from the aquarium shops or is there a cheaper alternative I can use?
I have heard you can use baking soda (sodium bicarbonate) but I would like some reassurance from others that this is ok before I use it. Also what can I use for the potassium side of things or is this in the baking soda too?

Could you please tell me if baking soda is the right thing to lift my KH in my Tanganyikan tanks or if you have any other suggestions of what I could be using, I would be very grateful for the information.

Cheers.

[Neakit]

some people use baking soda effectively, i my self only use it in a marine aquarium. If you want to make it more effective put a thin layer on a baking tray and put it in the oven for half an hour at about 180 degrees.

[sandgroper]

Baking soda for kh, Ebsom salts and marine salts for gh. cheers steve

[werdna]

Add limestone to your tank.
Limestone is a natural buffer.

[Tricoti]

some people use baking soda effectively, i my self only use it in a marine aquarium. If you want to make it more effective put a thin layer on a baking tray and put it in the oven for half an hour at about 180 degrees.

Neakit, thanks for the tip but could you explain why/how it makes it more effective after baking it?

Cheers.

[sydad]

Neakit, thanks for the tip but could you explain why/how it makes it more effective after baking it?

Cheers.

Don't mean to interfere, but I think I can help here. If baking soda (sodium bicarbonate) is heated sufficiently it loses carbon dioxide and water to form sodium carbonate (washing soda), which since it has lost some of the acid component gives a more alkaline reaction.

2NaHCO3 + heat = Na2CO3 + H2O + CO2

I would recommend not using this method, as the results may be variable. A better way is to purchase washing soda (also known as soda-ash) from a pool supply shop, and make a solution containing 6% sodium bicarbonate and 1% sodium carbonate by dissolving 6 grams of baking soda and 1 gram of soda-ash in each 100mls of water: this makes a satisfactory buffer solution used at 1-2 mls/litre of aquarium water volume (I suggest trying 1 ml/litre initially). If you cannot weigh the materials, use level teaspoons as a measure, remembering that each spoonful will weigh about 5 grams. (Serious aquarists should purchase a cheap digital kitchen scale that is accurate to about 0.5g.)

A better outcome is to use potassium bicarbonate instead of sodium bicarbonate, or, if you cannot source pot. bicarb., substitute the sodium carbonate with potassium carbonate which is usually easier to find. The idea here is to minimise the overuse of sodium in the aquarium, though the latter recommendation admittedly has minimal effect.

If using buffer solutions such as these, no more than two adjustments of the aquarium water should be effected without at least a 25% water change. Hope this if some help. If desired, I may be able to supply some help in sourcing chemicals.

Syd.

[Tricoti]

Thanks heaps for the info sydad, really helps.

Also thanks to everyone I have learned a bit on KH and what I need to use. This should save me time and more importantly money.
Now could I ask you guys to advise me on GH and if the epsom salts in this ebay sale is OK for me to use.

It is showing "magnesium sulphate heptahydrate". I'm not sure what the heptahydrate part is?

http://cgi.ebay.com....E:X:RTQ:AU:1348

Many thanks.

[sandgroper]

I just buy it from the super market, Faulding brand epsom salts (magnesium sulfate). Doesn't mention any other ingredient. cheers steve

[sydad]

It is showing "magnesium sulphate heptahydrate". I'm not sure what the heptahydrate part is?

http://cgi.ebay.com....E:X:RTQ:AU:1348

Many thanks.

Magnesium sulphate can exist in a number of hydrated forms, which is to say that it retains a certain amount of water (called water of crystallisation) when it is crystallised from solution. "Normally" the amount of water found in recrystallised magnesium sulphate is 7 molecules of water to each molecule of magnesium sulphate, and is expressed symbolically as: MgSO4.7H2O, hence heptahydrate.
The molecular weight of magnesiun sulphate is 120 daltons, while water is 18 daltons: so the heptahydrate is 246 daltons. This means that the heptahydrate contains over one half of it's total mass as water. Naturally this needs to be taken into account when a desired amount of hardness is being calculated.

Just to confuse matters a little, the heptahydrate on storage, if exposed to air can lose some of it's 7 molecules of water, a process called efflorescence. This can be annoying if precision dosing is planned. So the form of magnesium sulphate that we purchase as Epsom's salt (the heptahydrate) must be kept in a sealed container. It is possible to purchase magnesium sulphate in varying forms of "dryness", through to anhydrous (no water of crystallisation): the seller should always give an analysis showing just how much water is present. Oh and bt the way, the anhydrous salt is deliquescent, which means it absorbs water from the atmosphere, so it too must be stored in a sealed container if accurate dosing is planned with it's use.

Magnesium sulphate needs to be used with care if being used to increase total hardness. It is quite acceptable to have magnesium as the principal component of hardness, but not the sole component: this would lead to possible complications with some fishes. Calcium salts should also be used to create a "balanced" hardness, and can be added as calcium sulphate, which is also obtainable in differing hydrated forms. The safest to use is Plaster of Paris (the hemihydrate), which is of fairly low solubility, and should be prepared as a saturated solution using a large excess of water to prevent solidification.

If you are unable to, or not happy about calculating required hardness using the described salts, the best way is to prepare strong solutions of the salts in water, and add small quantities to the aquarium at a time. You will need a good quality hardness test kit to monitor the level of hardness attained. After a while the correct dosing becomes an almost automatic process. I would recommend having both total hardness and calcium hardness test kits. Total hardness minus calcium hardness = magnesium hardness.

Of course, if you use dolomitic rocks in your aquaria, the magnesium and calcium will tend towards naturally occurring levels.

Syd.

[Tricoti]

Many thanks again sydad. You are so knowlagable about this stuff are you a chemical scientist or something?
Alright I'm just going to ask, what do you use yourself? or what would you suggest I use for my Tanganikans?

Cheers.

[Tricoti]

Hi guys, today while buying some PVC pipe and fittings from Bunnings I come across a pool PH and Alkalinity lifter in a 2kg tub for $14.95, it had stamped across the front "active ingredient sodium bicarbonate".
Sorry for keep asking but is this going to be OK to use in my tank?

I priced up (what I have been using for the last 2 years) the African KH+ Potassium yesterday from my local aquarium and they are now asking for $199. for a 4kg tub. So you see why I'm now looking at other alternatives. What could they add to there mix besides sodium bicarbonate to make it so expensive?

Thanks again.

[Mr_docfish]

It would most probably be a mixture of potassium bicarbonte/carbonate.... rather than the sodium based bicarb.... it is considerably more expensive in smaller quantities.