Backyard Aquaponics
A place to discuss aquaponics

levels are all under control again here so the heating has been up'd again and we''ll se if i can push the limits on these SP again. Now that I have removed the yabbies it will only be poor water quality that will be there demise so some how I need to get another GB online. Im thinking about a lightweight medium like coco coir or something. any suggestions???

Okay I purchase some vermiculite and perlite the other day and have set up a wicking bed style growbed and a strawberry tower, which I was hoping would aid in my filtration. Nitrites have gone throught the roof again so heater is off again, and really need to get new pump that can handle a greater volume of water and head.

The wicking bed is around a 75:25 mix of vermiculite and perlite and approx 25ltrs tub. I have set it up so that it remains 3/4 full constantly and overflows directly into FT as the water is added. Its quite interesting stuff, both the vermiculite and perlite. I think I prefer the vermiculite over the perlite. (I actually didn't realise I had bought both)

I find the perlite crumbles to a very fine powder if rubed between the fingers and also has a very fine particles that could clog pumps and pipes.
The vermiculite is very similar but seems to hold its form when rubbed between the fingers and is slightly large particles which I feel would cause less (only slightly) problems with clogging.

The strawberry (or soon to be herb) tower is a long bag of perlite which I have mentioned else where about perlite strawberry towers, and sits upright in a planter pot and fills from the top and trickles out the bottom. I have now burried this into part of the wicking bed for stability and to reduce the head I was needing my poor little aquarium pump to handle.
Looks like I need a new pump as I need to run at least one GB 24/7 to handle the filtration of this system and the vermi/perlite GB's need to run on timer due to the water holding attributes of the two mediums.

I am also thinking of running an aquarium style filter system on this system due to the lack of room and abiliity to add more GB's to keep this system operational. I have read posts about biofilters for ponds and larger systems but I really need something small scale to aid in the filtration that my GB's can do. More research!

I am starting to think there must be something wrong in this system too becuase I have had a much greater fish load on this system before and not had spiking nitrites like this and the water temps have been much higher in this system over summer than what I am heating them too at the moment. Perhaps its time for a full cleanout and start over on this system. There is gravel in the base of fish tank so maybe it has gone beyond controlable?

Don't do that Bndybear... Perlite is an amorphous volcanic glass... it can literally cut you lungs up...

You should really wear a face mask when handling the stuff....

that doesn't sound to good!

I've read that if the load of ammonia is increased it can take a couple weeks for the bacteria which converts the nitrite to nitrate to catch up. its supposedly a much slower growing bacteria. I know in my system it took a couple of week to adjust since it was cold.

Matt

Temperature plays a major role Mattyry... but the age of the system plays a big part as well....

Yeah, Bndy, that's bad shite - very much in the same league as the silica they warn you about in cement, and several similarities to asbestos.

Thanks for the heads up! Cannot believe there are not warnings on these sort of things. I was actually going to do a google search for a MSDS or similar on the stuff.
Regardless I think I may have found the solution to my filtration problems. Checked out Nates vertical thread and found it very interesting and could be exactly the setup I'm looking for both on a small scale for filtration for this system and also for a possible future commercial system design.

You could always just run an external camister or box filter.... unless you really want to use a vertical system for extra growth...

This system is a bit of a roller coaster at the moment. Things are back in control after about a 25% water change and putting a second pump with filter cartridge fitted to just circulate and filter the FT. I still only have the one real GB filtering this system due to the advise about the perlite/vermiculite GB only to be used as a wicking bed.

Planted a mix of asian greens in the wicking bed and obviously the strawberrys in the perlite tower. Growth is definately visable in both mediums. One bok choy (I think) has actually shot straight to flower/seed since planting last weekend.
The Nitrates in this system are through teh roof.... 160+ according to the card. Guess thats what you can expect from lack of GB filtration and constant amm and ites spikes!

All my SP fingerlings that remained after removing my 2 yabbies from this system are still alive so I have concluded that it was yabbies as COD for the rest of em. Either directly from being caught and eaten or indirectly through stress. I will know for sure if these guys can survive the next few weeks after the high nitrite readings recently.

I am currently developing a similar vertical filtration/GB/NFT design to Nates that I will trial on this prototype system but I'll post more about that soon.
Untill then I have turn the heat up again and we will no doubt be going through the same scenario shortly when the nitrites spike again. I will eventually see some rapid growth on these SP even if summer gets here first!!!!

Just a thought, if you really wanted a cheap easy tower similar to your perlite one you could always grab a length of rockwool and do the same thing, the stuff i used to get came in a placky bag very similar, all you would have to do is add support somehow or suspend it from the roof.

I have only read limited info on Rockwool but it seems that it has very similar properties to the perlite/vermiculite ie: it stays too wet. This would mean that it could only have limited irrigation and probably not solve my filtration problems in this system.

I am extremely interested in Nate's vertical concept, and since it doesn't appear that he will have something to offer to us here in Oz very soon, I have decided to do a bit of small scale experimenting with a similar filter medium and design principle on my prototype system, after all, it was this system that began my experimentation with AP before I felt confident to do the 3000lt system outside. So let the experimentation begin again!

Fair enough....I would just build some FBT's (f*%&*%g beaut towers) like i had on my Kalgoorlie system, real easy to make and cheap

Yeah gnash those FBT towers are f$^!@# Beaut! I had thought of using gravel or hydroton in PVC tubes as well but was a bit worried about the weight of em above my glass fish tank, but for the outdoor system this is a great idea! And I love the way you made those holes. How did they go for cloggin with roots? and also growth. Were they run constant flow or timed irrigation.?

They were timed with the rest of the system and I never had a prob with them, ended up growing silverbeet and bok choy in them and they were fine.
Come time to remove the plants i just removed them from the frame and tipped them upside down