Backyard Aquaponics
A place to discuss aquaponics

If I treat gravel with trebel super phosphate to seal and make it pH neutral will it harm fish if some of the phosphates are not rinsed out?

It is nasty looking stuff and its possible some will not be rinsed away...

acid phosphate-should be good to grow fish with 3 heads if they survive

Dandee... why do you want to "treat" your gravel...

I don't understand.... be wary of transferring hydroponic or soil based principles, lores and practises.....

They have their purposes in the respective mediums for specific reasons and many will be detremental to fish health....

Fish are like canaries in the mining industry..... they react very quickly to minute changes in environment.... usually fatally.

The use of lime in other applications is done for many differing reasons not just pH....

The wonderful thing about aquaponics is that IT WILL find a natural balance over time... certainly without the pendulous swings of hydroponics and to a lesser extent soil based horticulture.

Many of the soil based fertiliser/lime type practises are employed to counteract the imbalances that previous human interventions have caused.

If the issue for you is raising the pH, then search and read through the many post on the subject on the forum...

Slow buffering can be obtained by the use of crushed seashells/coral...

Moderate buffering can be obtained by the addition of calcium carbonate

And faster buffering by the addition of Potassium Cabonate or Sodium Bi-Carbonate.... Sodium Bi-Carbonate however can result an imbalance of Sodium within a system.

Phosphorus is an essential element at certain stages of plant growth, particularly leaf growth... that's why super phosphates (single,double or treble) are so widely used for pastural growth....

But most "good" pallet feeds probably have sufficient levels of phosphorus within them... potassium is of more concern in the longer term as is iron...

Primarily because these elements can become locked out as pH drifts...

Dandee, there really is NO substitute for cycling your system patiently and allowing it to find it's own level.....

Your pH is an issue that needs to be addressed, not because it is in itself widely outside optimal levels... if you look at the optimal uptake of minerals in relation to pH then 6.5 (as in hydroponics) is probably about perfect....

Your issue however is that at the level of your pH it will effectively slow to almost nothing the action of the nitrifying bacteria in your bio-filter.... unless the colony is large enough and self-sustaining enough to cope

The addition of the microbial bacteria and aquarium gunk is a "massive" injection of a living colony of "good" bacteria. Will it be enough to stabilse/cycle your system in "quick" time ... maybe not

Hence you'll take longer to cycle.... so, as you are short of time then you need to address it....

To maintain that in the short term I would look to proven addtitions like potassium carbonate.....

If in doubt ... leave it out... as they say.... same thing applies to hydroponics I would have thought... generally there's no need to "add" any fertilisers of the "super phosphate" type

lol.. I know phosphates simulate a hormone.. I think it is ok, just wanted to know if anyone really knew if it was bad idea. I do it for my hydroponics and it works great, but now I'm talking about fish..

The phosphates bond to the lime ect in the gravel to make a non water soluble form. It can be washed off after that. It simply prevents the gravel (& any lime in it) from raising the pH..

My goal is a self sustainable system that does not require the purchase of buffers of anything else..

I thought of using CoCo Coir Peat instead of gravel, but I have not seen any thing good said about CoCo Coir.

True Dandee, plants love it.... but you don't have any plants at the moment and none that will need or benefit from it in the near future...

What you have very shortly is FISH.... and it's their health you need to tailor things to..... the plants will take care of themselves (pretty much) when the system is up and running.... just look at all the photographic evidence here on the forum

Don't seal the gravel. That would eliminate crevices and pits in the stone for the bacteria to live. On the assumption that your gravel is raising the pH, that is actually going to be a good thing in the long run. As the nitrogen cycle gets established, it will actually pull the pH down. You'll need to have the activity of the rocks to help even things out. I have 28 pounds of calcium carbonate in my system, and still have to add potassium bicarbonate every day to hold the pH up.

Great answer janet! Thank you!

If you are worried about your "gravel" Dandee, then wash it.... it should remove most of anything that may be coating it.... and there are many here who would say that it is part of the initiation of aquaponics...

Others are tending toward the belief that not washing it retains beneficial "rock dust" trace elements which the plants utilise later...

Most people though are using a crushed "granite" gravel..... normally almost absent of any large degree of lime.....

Are you thinking of using "limestone".... if so then I would think that given the pH of your well water, utilising calcium carbonate "limestone" might in fact be highly beneficial and naturally buffering

What ever happened to the KISS rule?

Do what works. That is the whole purpose of this massive amount of information here... By all means experiment, but get the basics done first.

I use crushed pea gravel, at least 10 systems in this forum uses it. Others use blue metal, clay balls... it doesn't matter what you use..

What you want is huge surface are, relatively clean and cheap growing media. Keep in mind that the plants are only a byproduct if you will to a cycled fish system. They don't matter, the fish do... the growing media is more important to the fish than it is to the plants.

Well put TC!
On the weekend someone suggested "why try to recreate the wheel, round is good"
also if the fish are completely happy the plants will be happy too.

Janet got it pretty well covered.

sealing your gravel will need MORE ph up buffers added and REDUCE the surface area of the gravel available for the bac.

As rupe stated often in hydroponics a sterial environment is aimed for. Aquaponics is the opposite.

JP, did you ever do a test on your KH/GH ? i still want to test my theory about the CaCO3 not buffering well anymore due to high GH/KH.

If it turns out to be tru then you can just use some of your AP water for dirt gardening and replace it with fresh water to lower the KH/GH

Steve

I have not purchase a new KH/GH kit, although I suppose I could. Might be interesting to see how the potassium bicarbonate affects it all.

my theory goes thus: something along the lines of very high carbonate hardness inhibiting further CaCo3 dissolving

Hmmm, interesting theory, Steve. I'm totally swamped right now, but I'll try to swing by the LFS and see if they have a kit.