Acid and Base Chemistry of Aquaponics Brief Overview

It’s all about water

Acid and base chemistry has its roots in the actions of water.  Water (H₂O) does not solely exist as H₂O as it sits in a glass on a table, but rather splits into its ionic (charged) parts.  H-OH breaks into H⁺ and OH^-.  H⁺is a hungry proton, looking for another compound to attack to balance its positive charge and become neutral.  This is what makes acid “acidic”, and why hydrochloric acid (HCl) will eat your flesh…it’s all about those hungry H⁺’s looking to balance their “+” charge.  Similarly, OH^- is a hungry hydroxide looking to balance its charge by attacking other compounds.  This is what makes bases “basic”, and why lye will eat your flesh…it’s all about those hungry OH^-‘s looking to balance their “-” charges.

How water is the acid

Let’s say your fish tank is full of water sitting at room temperature.  Some water will remain as H₂O molecules, while some dissociate (split) into H⁺ and OH^-ions.

Let’s add 4 parts hydrochloric acid (HCl) to the water.  Acid will also dissociate into H⁺and Cl^- ions.

The hungry H⁺’s from HCl will attack the OH^-‘s in the water, turning them back into H₂O.

Since 4 OH^-‘s are removed from the solution, we now have an excess of H⁺.  Thus, by HCl making H₂O less basic…it becomes more acidic. Our extra choride ions are just floating around, doing nothing as spectator ions. 

How water is the base

Now, let’s add 4 parts ammonia (NH₃) to the original neutral water in the fish tank.  Ammonia is uncharged, so it dissolves but doesn’t dissociate in water.  However, nitrogen is famous for having an extra pair of electrons (negative charges) that are hungry for positively charged species.

 

The hungry electrons on ammonia (NH3) will steal 4 H+’s from the water, turning it into the positively charged species ammonium ion (NH4+).  Since 4 H’s are removed from solution, we have an excess of OH-‘s.  Thus, by ammonia making H2O less acidic…it becomes more basic.

 

Where does pH come into play?

pH is based on logarithms.  Specifically, it is the negative log of H+ concentration.  The pH scale only goes from 0-14.  There is nothing more or less.

If concentration of H+ is 10^-14 in a solution, that means its concentration is 0.00000000000001.  This is a VERY weak acid.  Calculate -log(10^-14) = pH of 14.  This VERY basic because not much acid.

If concentration of H+ is 10^-7 in a solution, that means its concentration is 0.0000001.  Calculate -log(10^-7) = pH of 7.  This is neutral, like pure water.

If concentration of H+ is 10^-1 in a solution, that means its concentration is 0.1.  Compared to 10^-14, this is a VERY strong acid.  Calculate -log (10^-1) = pH of 1.  This is VERY acidic. 

So why bother using pH at all?  Consider this:  An H+ concentration of 10^-1is 0.1.  An H+ concentration of 10^-7is 0.0000001, which is 1,000,000 times LESS than 10^-1.  Rather than making it difficult for the layman with calculating exponents and logarithms, pH makes things easy by saying pH 1 and pH 7.  Let’s recap:

Acid = LOW pH (below 7)

Base = HIGH pH (above 7)

A Good Malay Feast Kedai Makan Rahmat

Date:  Mar 29, 2015

Yesterday, we went into Malaysia to visit my father’s grave.  My dad passed away 26 years ago on Mar 23.  It is before Qing-Ming, therefore, we always came in to pay respect during this time.

The grave is around Kong Kong, which is close by Pasir Gudang,  So, we decided to search on Google places to eat after paying respect.

And we found this place.  Apparently a famous Malay restaurant by the seaside.

Wow!  The restaurant only sell afternoon meals.  And close on Friday.

The restaurant is just like those you find in Batam or Bintan.  But this restaurant sell Malay food.

The restaurant is full of people.  People who is hungry just like us.

The restaurant is just beside a fishing village.  This is where they supply all their sea food I suppose.

Let’s check out what food they serve here...

This is ikan Siakap.

This fish is on EVERY SINGLE table.

They slow fry the fish into very crispy.

Inside and under the crispy skin is very delicious meaty fish.

Every table also have this fry prawns.  Very nice and fresh prawns.

The prawns go very well with this sauce.  Some kind of soya sauce with a bit of Onions, and lime, and chilli in it.

The fish taste great with this home made sambal.

This Tempeh is REALLY GOOD.  It sort of taste like banana, a bit sweet a nice.  Especially mix with the samba chilli.  This is actually fermented soybeans.   

The beef rendang is very tasty too.

The chilli ayam (chicken) sauce is nice.

Fried kampung chicken.

We never meant to be here, but here we are, and it is the only restaurant around where we are, deep inside a Malay fishing kampung.  So, let’s enjoy ourselves.

OK.  The food was delicious.  Even the banana.

There is even TV show recommend this place.

This restaurant is opened by important people in Johor.

It is located just slightly below Tanjong Putri Golf Resort.  Now we ate so full and did not have a chance to eat Famous Mee Soto.  hahaha

This is the address and their name card.

Map behind their name card.

And here comes the bill.  Wow.  79 Ringgit.  About SGD$30 for a nice full table of food.  :)  Good value and delicious.