Backyard Aquaponics
A place to discuss aquaponics

Oh and my EC reading currently is 760uS/cm

Just had to ask as I came across this discussion as I was thinking to build dual RFF to be able to slow the flow. And yes mine was also planned to come from a "overflow" drain to keep the water cleaner going towards my DWCs.

Thanks!!

Cookie, whats your EC usually? I'm at 452. I top up my system water with rain water that has an EC of 30.

Here is a research paper comparing swirl filter vs radial flow filter. RFF wins hands down.

lol I mentioned it before.. but ots 1000 uS/cm.. but thats because of adding previously the supplements of potassium.. magnesium.. and calcium.. but in the small system im not going to supplement inorganic salts into that and only use MT water as my only additions to see if plants can grow only on fish waste.

ok ok cool.. any questions feel free to ask.. we are always able to help.. and Swed always have information... I dont kno how Swed get it..

I was thinking of splitting flows to have a small stream leave the bottom of the fish tank and divert this tp the RFF.. by doing this your RFF can be sized alot smaller than usual.. and the rest can go into the media bed. but for this to be effective your FT must mimic a clarifier firstly to allow for setting in the center.. too much fishes or to fast or to slow a flow without a swirling action will not give settling properties as expected.

Cookie, that's it. Tanks should be round for this to be most effective. Rule #1 [WINKING FACE]
Oh, on the molasses part I was adviced never to use it and that the reason for plant death could have been the sodium content of the molasses.. Don't know why I forgot about that when posting yesterday.

On the dual RFF I had that similar thought before. I decided against it. Something else to consider is a self cleaning sieve filter. Search on YouTube for mr1superb, he has some really nice diy sieve filters. Only drawback to them would be that you need more drop after sieve filter if using gravity to flow into a netting tank or other..

Best way I have found is dual outflows from a round fish tank as described above making the fish tank work as a big swirl settler.

Mind you guys I am not an expert on this, these are just ideas I have read about in either aquaculture books or learned from others with more experience. I still have not rebuilt my system to the specs I would like. Its in,my garage and I have grown out of space and also while a system is operating it always makes it harder to start modifying it since flow has to be turned off. Don't feel like killing any of my fishies just because I got stuck somewhere in the process of modifying.. Lol.

Hi lmannyr,
Yes the RFF s are supposed to,be,more effective.
On EC readings. Its not everything. If you have one nutrient that is low. It will be the limiting nutrient for growth.. You can have high EC readings yet poor growth. Don't ask how I know [WINKING FACE]
I also learned from Paul Van Der Werp that phosphorus has s way of being adsorbed by clay media balls such as Hydroton. Which may our may not make it unavailable in your system.. I had tested for phosphorus and basically had 0. So I added triple super phosphate to bring it up to 2-5ppm in combination with also adding some Epsom salt (low on magnesium possibly) growth picked up almost immediately after adding the phosphate. Epsom had been added about 7-10 days earlier.. So I think the limiting nutrient was phosphorus in my case but that magnesium most likely was needed as well.
In case of phosphorus the were two possibilities in my mind.
1. Absorbed by clay balls
2. Tied up in bacteria that were too slow in releasing the phosphorus back to the plants.

Just my thoughts hope that helps

If not molasses, what do you use for sucrose content for bacteria growth?

I always wonder if plants, like animals and bacteria, can comsume their nutrients bounded to a carbon source like we do. eg when we eat food all the minerals and nutrients are bounded to a Carbon and when we digest our food.. the minerals are released into our body. this is our main intake of minerals..
then there is the minerals in tablet form.. ita basically the same as in food and sometimes its the same amount found in food as well.. but no matter the amounts of supplements we intake.. it cannot replace the need to eat food for our nutrients.

So in saying that.. how are we not sure the same applies to plants.. how are we not sure that plants can 'eat' bacteria and other organic sources of food to absorb they nutrients.. I for one don't know the answer to that.. but I'm always fascinated to know the answer to that.. what u all think.

From my research it seems the use of a carbon source and the use of different types of carbon sources actually develops different types of bacteria.. they acts as a selector similar to the difference between herbivore and carnivore...

For our purposes in mineralization of Solids.. no additional carbon source is needed because there is enough carbon in the fish poo.. the problem is that bacteria prefer liquid carbon sources but the fish poo is in a solid carbon form... and hence anaerobic digestion is needed firstly to create the liquid carbon needed for bacteria growth.. and then this is where we switch to aerobic digestion which quickly uses the free liquid carbon to build bacterial growth and mineralize the fish poo.

Cookie or Swede,

I figured one of you 2 had experimented with this before. So here goes. If someone was to put a IBC inline between the FT and GBs as a settling tank. With both the inlet and outlet at the top. Which would give a constant flow across the top 1/3 (I'm guessing). The bottom would create an anaerobic zone. Sort of like a MT. If air was cycled with a timer in the bottom of the IBC. Say on only 5min an hr. Wouldn't this work as a slow release MT? Constantly mineralizing the settled content and being replenished with more. While the mineralized content is also constantly being reintroduced into the systems main flow. Thanks And yes I am asking because I have the better part of a IBC just setting around

the idea of using an IBC as a setting tank is a great idea.. using it as a inline MT.. umm not too good. I have experimented with that inline MT.. if you back track in my Thread you may see what im speaking of.. the problem of adding air to to the bottom is.. 1. it well re-suspend the solids and the solids will flow forward... 2. in the process of mineralization alot of retention time is needed in order for complete breaking down of the solids. You see in anaerobic digestion alot of ammonia is released into the liquid.. as you add air alot of this ammonia is initially converted to Nitrites and Nitrates.. and if ammonia hits as high as 8ppm like mines.. nitrates hits over 300ppm and nitrite hits over 40ppm... as the time passes other bacteria uses the extra ammonia for growth.. eventually all this biological growth leads to increase biological oxygen demand.. and because there is high levels of nitrite in solution.. denitrification begins where the excess nitrates reacts with the nitrite to produce nitrogen dioxide and them to nitrogen.. surprisingly this process is happening while air is being added till ammonia nitrite and nitrates hits 0ppm..

So in conclusion inline MT will lead to incomplete conversion and will lead to nitrites spikes.. and hence offline MT is ideal plus this allows you to get solid nutrients for garden plants..

Thanks Cookie. Saves me from wasting money.