Shilo

As a side note:  I used cloudy ammonia to cycle mine a few years ago.  The amount of surfactant added is very minimal and didn't effect the process, 100% water change before adding fish (which should be done anyway) and not a problem.  If the food doesn't work, give it a try.
A lot of what you read are from the over cautious who never tried it and are just repeating what they read from others who have also never tried it.  When doing research I didn't find one case where somebody used cloudy ammonia and experienced adverse effects because of it.

Yup, Homebrand with the red on the label (still got 2/3rds of it left on the shelf). The cheapest I could find, figured the cheaper it was the less other chemicals would have been added since it would cost the manufacturer.
 
 

Have you tried a different thermometer?  The tank temp could really be 25C but the thermometer is broken and stuck on 29.5C.   

They are a powerful fish and can jump.  May never happen but since they have the ability it would be taking a risk, all they need would be a scare (mine jumped from a quarantine tank once). 

Duckweed.  Tomorrow the numbers would have doubled, and the next day doubled again.....   Some fish like gold fish eat it but yup removing every last bit is the only way to go.   It doesn't like too much surface movement so the return aimed at the surface etc will help but removing is the only sure way (every bit as even 1 leaf will mean it returns with a vengeance).

Think dilution.  The more diluted the ammonia is the safer for the fish. A small amount of ammonia in the water (below 1ppm) won't harm the fish and the bacteria population in the filter will eventually grow enough to deal with this amount.  When this happens another fish can be added to increase the amount of waste etc, the ammonia levels rise again then time is needed for the bacteria population growth to catch up to this level and so on.    
Advantage:  you get to have life in your tank straight away.
Disadvantage: You have to keep a constant eye on the ammonia then nitrite levels (the fishes life is at stake) and it takes longer to get a fully stocked tank.
With a fishless cycle you can get the ammonia level up to 4ppm so more food for the bacteria = faster bacteria population growth = faster cycle = fully stocked tank sooner. 
I won't say " a couple of small clowns in a 140L is Ok" because it all depends on whats considered small and how fast the bacteria population grows (depends on filter system, water parameters) etc.  Every tank & situation is different. Instead if you go this route then test 2x a day and if the ammonia then the nitrite levels get near 1ppm do a water change.  Keep doing this until the tank is fully stocked. This is why the fishless cycle is more forgiving and safer for a beginner.   Throwing a couple of fish in a tank, waiting a few weeks then throwing in the rest may work out Ok for you, but there is a good chance it won't.
 

Repair.  Get some glass cut for a Eurobrace and it will be a simple job of siliconing it on.  You won't even need to remove the fish, just lower the water level a bit for the couple days while it drys.  If the centre brace didn't last it is no use doing another one, a Eurobrace should be much stronger as it supports more of the glass edges.   
Of course on the other hand this is the perfect excuse to get a larger tank! 

Unfortunately "Honeycomb" is just a marketing brand like "Dragonstone" so tells you nothing.  It all depends on what minerals its made off, the vast majority of any rock would be safe in the tank, the main exception is limestone.  Limestone will increase your PH because it is so alkaline.  If you can get a bit test it with some sort of acid, even strong vinegar will work.  If it bubbles it will effect the PH levels.  There are no minerals that I know off that are acid and will lower the PH (this is normally organics like wood, leaves etc).
 

Depends if you want the stand to follow the curve of the tank front or not.  Following the curve will look good but be much harder to do.  Building the stand as a rectangle is the easiest way.    You don't need to go overboard but remember 850-900kg  need to be supported.  Reckon it can be done with 2 by 4's but double up them at the corners and in the middle supports.  When planning it out try to make sure the weight is supported by the wood and not any nails, bolts or screws etc and put some angled or horizontal wood between any verticals in the back and side to remove any risk of the stand collapsing sideways.

If the water from your concrete tank has a low KH then I wouldn't worry about aluminium leaching out, the water tank would be very well aged for a low KH and any aluminium would have leached out long ago.  Fresh concrete should have a high KH because it is made from calcium carbonate.
Before fiddling with the water chemistry for plants, grow some first and then work out what if anything is missing.  The plants will tell you with the colour of any dying leaves what they need.   Same for the BB, I wouldn't consider 6.8 as very soft water & also had no problems when I was on tank water.  A lot of minerals will be added naturally from excess food and waste of the fish and BB.
Apply the K.I.S.S principle and adjust what is needed when you know it is needed.

Mines also gone off its regular food.  Could be change of season with the water warming up.  It does this now and again so not too worried about it (Nitrates <10ppm before water change & no ammonia or nitrites).  But a change of food especially live food gets it eating now and again, currently its earthworms.  They have to be wiggling right past its nose before it decides to eat.  The fish is healthy and apart from not eating hasn't changed its behaviour at all so not a problem.  The previous times it stopped eating for a few weeks it would suddenly go on a binge & eat everything in sight (which is why I don't have anymore small fish in the tank)......

Mines also gone off its regular food.  Could be change of season with the water warming up.  It does this now and again so not too worried about it (Nitrates <10ppm before water change & no ammonia or nitrites).  But a change of food especially live food gets it eating now and again, currently its earthworms.  They have to be wiggling right past its nose before it decides to eat.  The fish is healthy and apart from not eating hasn't changed its behaviour at all so not a problem.  The previous times it stopped eating for a few weeks it would suddenly go on a binge & eat everything in sight (which is why I don't have anymore small fish in the tank)......

Suppose you could always put a complaint via Trademe.  A lot of adverts there are not original photo's of the items - big tell tale is a new item with a plain white background with the same image used on Ebay etc listings.  Most people & even businesses don't realise that all images on the web are copyrighted to the original owner unless the creative commons licence has been applied to them.   
Even if they do come to an agreement with you to use your pics, for their own sake and those of purchasers HFF should state on trademe listings that the image represent the species but not the exact fish for sale.  Otherwise for an expensive fish like an Arowana (different grade of fish etc then advertised) they could be taken to the disputes tribunal.

Just got a copyright infringement settled this morning when another accommodation business was using one of the photo's from my website for her own.  First a nice polite email stating that what they are doing is wrong (their website was made by another company) and asking her to correct it, then after a month sent her a more professionally written email stating that she was infringing on my copyrighted material, it has to be taken down by the end of the month and legal avenues will be implemented if it isn't removed.  It was changed this morning.  
In your case I would:  Put a copyright notice on the bottom of the web pages like in my case "Copyright 2017 © Kawhia Camping Ground"  Then send HFF an email asking them to stop using your photos else further action will be taken.  
Have a look at this pdf for info: http://www.copyright.org.nz/html/blob.php/Infringement+of+copyright+-+What+should+I+do.pdf?attach=true&document=511&filetypecode=1&fileId=131
HFF's problem is most likely that it is not them updating the website but a web designer & the designer is just taking the easy way out by copying other peoples work.  The designer may not even be NZ based.  If they think you are serious then they will most likely stop doing it - I doubt it would ever have to go to court but the threat of that helps.

When you turn off your pump (or there is a power cut) the water will siphon from the return pipe in your tank down into your sump.  If your outlet of the return pipe is on or just below the water surface it will only siphon down to this level.  But if your outlet is near the bottom of the tank all the water above it could siphon out.  Can be easily stopped by using a check valve (not recommended) or a small hole drilled through the return pipe just below the water surface as a siphon break (will suck in air and stop the siphoning action). This will mean the water will only siphon out to the level of the hole you drilled.
But what ever method you use you need to allow room in the sump for the extra water that will flow into it before the siphon action breaks and stops.  If you use an overflow on the sump instead then when the pump starts up again the tank will fill back up to its normal level but the sump will be drained.
An overflow is only needed on the sump if you plan on using an automatic drip water change system (water continuously dripping into the tank or sump with the excess going out of the overflow to avoid having to do manual water changes).

When you turn off your pump (or there is a power cut) the water will siphon from the return pipe in your tank down into your sump.  If your outlet of the return pipe is on or just below the water surface it will only siphon down to this level.  But if your outlet is near the bottom of the tank all the water above it could siphon out.  Can be easily stopped by using a check valve (not recommended) or a small hole drilled through the return pipe just below the water surface as a siphon break (will suck in air and stop the siphoning action). This will mean the water will only siphon out to the level of the hole you drilled.
But what ever method you use you need to allow room in the sump for the extra water that will flow into it before the siphon action breaks and stops.  If you use an overflow on the sump instead then when the pump starts up again the tank will fill back up to its normal level but the sump will be drained.
An overflow is only needed on the sump if you plan on using an automatic drip water change system (water continuously dripping into the tank or sump with the excess going out of the overflow to avoid having to do manual water changes).

I did one not long ago.  Used some polystyrene sheet from the hardware store which I carved "boulder" shapes using an osculating multi-tool and a small rasp.  To build up the boulders thicker then the sheet just cut excess poly to shape then glue in place with a hot glue gun.  Use tooth picks to put them in place before glueing to test that things look right. Once the shape has been defined either sand it (120 grit) or use a hot air gun or both to clean it up. If you make a mistake just cut off the offending bit and stick on another piece of poly in its place.
I then coated mine with cheap tile grout which worked well for a month until the tanks PH level started to sky rocket.   Normally this happens as soon as water is added then reduces over a few weeks but I removed mine and coated the grout with epoxy.  While the epoxy was still wet I poured sand (black beach sand on the humps and pool sand in the hollows) on it to make it more natural looking.  Been great so far.
Things to think about when making one:
 Avoid any straight lines, there are very few in streams, lakes, etc and they look out of place as I found out with the first attempt when I made too many straight lines in error.  What I was going to do and should have done is to take a photo of a water worn rock face or bank and draw it on to the polystyrene before carving.
Polystyrene floats so you will either have to jam in between the tank bottom and top braces or silicon it to the back glass.  Depending on your tank you may also have to cut it into 1/2 or 1/3rds to get it in.  Make the cuts flow in the hollows like a jigsaw so the joins are not noticeable. 
When designing it use the opportunity to carve the back to hide any returns and other plumbing.
Lastly: Carving polystyrene makes a huge mess. If you do it inside you will be finding polystyrene beads & dust for the next century despite a major clean up afterwards.  If outside then your neighbours will be wondering why it is snowing at summer! 
 

Where's my food!  Its been 2 hours since you've fed me!!!! 
 

Its fine with the others.  As above the GK is the boss of the tank and even tries to take food out of the eels mouth - the eel just ignores him.  Bullies move out of the eels way but only when they are about to be pushed not because they are scared of it.
My fingers are another matter as it can bite when hand feeding because my fingers smell of food and its eye sights not the best  (doesn't hurt).  Interesting to watch him feed because when hunting for left over food it will start to swim straight past a piece then back up and grab it.  Think he approaches a piece of food as the smell increases then when it starts to diminish he can pinpoint which side it is on (via nostrils sticking out either side above his mouth). 
P.S. the white line on its back is just something stuck to its slime coating.  Thought it had ich the other day only to realise it had grains of sand stuck to it.
Butch also wanting to be fed despite a stomach stuffed full (better count my Inanga's again).

Its fine with the others.  As above the GK is the boss of the tank and even tries to take food out of the eels mouth - the eel just ignores him.  Bullies move out of the eels way but only when they are about to be pushed not because they are scared of it.
My fingers are another matter as it can bite when hand feeding because my fingers smell of food and its eye sights not the best  (doesn't hurt).  Interesting to watch him feed because when hunting for left over food it will start to swim straight past a piece then back up and grab it.  Think he approaches a piece of food as the smell increases then when it starts to diminish he can pinpoint which side it is on (via nostrils sticking out either side above his mouth). 
P.S. the white line on its back is just something stuck to its slime coating.  Thought it had ich the other day only to realise it had grains of sand stuck to it.
Butch also wanting to be fed despite a stomach stuffed full (better count my Inanga's again).

Its fine with the others.  As above the GK is the boss of the tank and even tries to take food out of the eels mouth - the eel just ignores him.  Bullies move out of the eels way but only when they are about to be pushed not because they are scared of it.
My fingers are another matter as it can bite when hand feeding because my fingers smell of food and its eye sights not the best  (doesn't hurt).  Interesting to watch him feed because when hunting for left over food it will start to swim straight past a piece then back up and grab it.  Think he approaches a piece of food as the smell increases then when it starts to diminish he can pinpoint which side it is on (via nostrils sticking out either side above his mouth). 
P.S. the white line on its back is just something stuck to its slime coating.  Thought it had ich the other day only to realise it had grains of sand stuck to it.
Butch also wanting to be fed despite a stomach stuffed full (better count my Inanga's again).

Its fine with the others.  As above the GK is the boss of the tank and even tries to take food out of the eels mouth - the eel just ignores him.  Bullies move out of the eels way but only when they are about to be pushed not because they are scared of it.
My fingers are another matter as it can bite when hand feeding because my fingers smell of food and its eye sights not the best  (doesn't hurt).  Interesting to watch him feed because when hunting for left over food it will start to swim straight past a piece then back up and grab it.  Think he approaches a piece of food as the smell increases then when it starts to diminish he can pinpoint which side it is on (via nostrils sticking out either side above his mouth). 
P.S. the white line on its back is just something stuck to its slime coating.  Thought it had ich the other day only to realise it had grains of sand stuck to it.
Butch also wanting to be fed despite a stomach stuffed full (better count my Inanga's again).

Where's my food!  Its been 2 hours since you've fed me!!!! 
 

Tanks going well.  Butch the GK is living up to his name in both shape and attitude as he rules all of his domain.  The 2 female Redfins are their cheeky self & I still haven't got my a into g and got some males for them.  The Inanga's have dropped in numbers from 15 in November down to 9.  No dead fish found and since it was only the smaller ones that disappeared and the GK looks fat each time I know the cause.......  As the GK grows I expect the Inanga population to proportionately fall.
One major change was adding a small shortfin eel in December.  I hadn't seen the cray for a few months so decided it must have died in its hole so got the shortfin.  It is not something I recommend for a tank even one of 500ltr as it will outgrow it (the originally 15cm eel has doubled its size in only 5 months). But it is very intelligent & entertaining.  Within 2 days of getting it, it was coming to the surface to feed from my hand.  Feeding time is 4.30pm and will make itself known during that time and insists on being hand feed even if my fingers are a couple inches above the water. It also puts up with being petted and will come out of hiding & weave itself through my fingers during the day (good party trick for camp guests).  A couple of weeks ago I spotted the eel and the cray having a territory dispute over a hole so the cray is still alive and kicking butt.
The tank is in the reception area of a camping ground and very few NZ'ers seem to realise that they are natives.  After I advise them that they are natives they automatically assume that its a saltwater tank because "only trout live in streams".  Depressing how many can recognise a native bird but have no idea of freshwater fish.  

One 625ml pack should do the tank & probably the background.  You only need to do the inside of the tank if the outside is painted with an enamel paint.
Materials required for tank:
Ply, pva glue, stainless screws, epoxy, epoxy colouring (if required), putty to fill in screw heads, paint, silicon, glass for viewing panel.
Tools:
Circular saw, jig saw, drill / screw driver, sand paper, plastic sqeegie, router (optional), paint brush.
Materials for 3d background:
Polystyrene, toothpicks, grout, epoxy to seal, silicon to glue to tank.
Tools:
Fine saw, sharp craft knife, glue gun, small sureform, sand paper, paint brush for dapping on grout, paint brush for epoxy coating.