Backyard Aquaponics
A place to discuss aquaponics

Hey everybody

I'm relatively new to aquaponics, but I thought I would share my system on here. It's been up and running for a couple weeks now. I have 19 goldfish, 3 black moors, and 1 pleco fish in a 40 ish gallon tank (not sure exact size) and the water is pumped up to a 2x2 growbed filled with grow stones (made from recycled glass). It is supposed to be flood and drain but I don't have a timer yet so I have been doing it manually when I am home, but that's it.

I don't have any ph, ammonia, nitrite, or nitrate levels yet, because I don't have a kit. Being a broke college kid sucks.

This morning I noticed some white stuff growing on my media? Anybody have an idea of what it is?




Also, a pic of my workers

...and all this time we thought you were a rich movie star!

did you add salt or anything else to the system? i think the white powder is the result of the salt?

No I never added salt.

The white particles are also accumulating on the stems of a few seedlings I have in the GB.

have you used any ph adjusting products? or any kind of sodium?

You think your white stuff was bad.....

I have no idea either what that stuff is also, but I am salting at around 1ppt.

There is certainly something in your water. It is all up the side of the aquarium too. It might be worth googling to see what is in your local water supply.

Another thing, i would save your money on a timer and just run constant flood. It looks like your water level is barely covering your pump and with a bit of evaporation it might start running dry. Also there isnt much left in there for your fish

It is salt.

What brand of expanded clay did you buy?... Before the factory stopped producing there were whole batches of Hydroton/Hydrogran returned because they contained excessively high amounts of salt. Supposedly the Canna clay and a couple of others also came from the same factory.

Supposedly that is why they stopped producing, they had a number of clay pits around Holland and Germany that they'd been extracting clay from for decades and they'd depleted all the good clay and were only left with clay containing high amounts of salt. They looked at importing clay from elsewhere in Europe but supposedly costs were inhibitive.

A number of my customers have had this issue, as have I, in both one of my display systems and my kids AP system at home. I would temporarily redirect the drain from the GB in question to a waste bucket and flush quite a few watering cans of fresh water over and through the clay, then hook the drain back up.

The stuff on the side of my tank was there when it was given to me. I tried scrubbing it all off but that's all I could get. The only pH adjusting product I have put in the system is a basic aquarium water starter called "Start Right." But that was a few weeks ago at least.

The clay in there was also donated to me by a friend.

@RSEVS3-- The first pic where the water level is barely covering the pump was when I first started the system, the other one is a more recent pic. I don't think constant flow with this grow bed is a great idea because there isn't good water circulation throughout the GB. The water is being pumped up through the input valve which is a few inches lower than the output valve, but right next to it. Once the GB fills up to the level of the output valve, it starts to drain out. So the water on the other side of the GB isn't really moving at all. The GB was designed for a flood and drain.

Thank you everybody for your responses

I would put money on salt too.
To test, I would try the good old fashioned lick test personally, whats the worst that could happen!

White on the sides of the tank is calcium buildup.
A brand new razor blade run along the edge of the glass may scrape it off.
Thats about all you can do now that the tank is full.
You might be able to get some very weak HCl and rub it on there, leave it for a few hours and scrub it off.

That was pretty much the story that I heard as well Yabbies.... but that it was only related to a few batchs.. primarily shipped into the UK, and around Europe.... and related to depletion and quality of the clay reserves...

But I've since been told that the problems at Hydroton... were actually related to a falling out between business partners... and that the clay supply is still productive and quality assured..

And that one of the partners has now bought out the other,.... and will be resuming production shortly....

Fair enough mate. Sounds like FnD is the way to go

For a tank that size you could always just chuck the fish in a bowl for an hour or 2 while scrub the inside of the tank with HCl. Thats if you are worried about the stuff on the glass. You could flush your media with fresh water to try and wash some of that salt stuff off while you were at it...

I think the whole thing might've been a furphy... so they could raise their prices while clearing out stocks of bags that contained unacceptable levels of smaller pellets.

A supplier here in WA has still been getting clay from the same factory, just not branded Hydroton/Hydrogran, so I don't think it has stopped production. Supposedly the clay is still 8/16 grade and the salt levels were within acceptable levels, but I've seen the bags and there is far more beads down around the 8mm size than there is up around the 16mm size. The supplier has told me that the regular expanded clay, that we knew as Hydroton/Hydrogran, will be available again soon, but under a different brand name and with a heftier price tag.... who knows?... we can only wait and see.