Need Help Settling A Disagreement-Sump Tanks

[Darlene Cerullo]

Hello everyone! I recently finished Sylvia's Aquaponic Gardening book and feel empowered to make my own system. My goal is to eventually have an Urban Farm using Aquaponics, but I would like to start on a small scale first. I have about 500 SQFT of warehouse space at my disposal (lucky me!)

Our system will be a hybrid system--we will integrate media beds and DWC rafts. The water will be gravity fed from the fish tank to the media bed then to the DWC. Then at the end of the DWC there will be a pump (or sump w/ a pump?) sending the water back to the fish tank. 

My question is this: can we pump the water back into the fish tank using a pool pump or do we need to utilize a sump tank? I am of the belief that we need a sump tank, but my business partner does not agree! I need a very good argument for why we need a sump tank--any suggestions?? Thank you :)

[Darlene Cerullo]

Oh wow.. sounds like you will have lovely new space. Thank you for the compliment! We had to make many adjustments, but I think we have it figured out. Have you considered a bell siphon for your media bed? It works great!

[Jeff S]

Wish I could redo my space. 1st I'd double the size. I'm curious too why you chose not to use bell siphons Yaacov. I'd stick em right in the middle and drain from all directions. I've recently seen a video of a guy who just has his on a timer that turns on long enough to fill the beds and off long enough to drain them. Uses a standpipe just like a bell siphon but there are small holes in the bottom that will totally drain the beds. You'd have to have enough flow to override the drain holes while filling though.

[Yaacov Levi]

I didnt mention the Bell Siphons but they will be in use. I will have a timer too, 15 mins on, 45 off. It will have lots of fine tuning during the run-in period. 

[Jeff S]

Why slope your bed instead of centering the siphon?

[Yaacov Levi]

Gravity works.

[Darlene Cerullo]

Hi everyone! I know it's unrelated to the sump tank question.. but I was wondering if anyone knew the answers to a few lingering questions that I have. We've already started to plant into the media bed by broadcasting seeds into the MB. Surprisingly, things grew really well! However, we would like to begin starting our plants in the germination area that we built. In the picture that I posted, it's the white shelving system. Here are my questions:

#1. What type of water do you start your seeds in? AP water from your system? Do you add any special nutrients?

 

#2. Do you have a recommendation for a pump for this part of our system? We have 6’ of head and 4 12’ troughs for our germination/nursery area. We would love to invest in a good pump that isn’t going to have any problems. 

 

#3. How often should we time the pumps to run and for how long?

 

#4. According to someone I spoke with, we need to continuously increase our kH which will keep the PH stable. Do you know the formula or calculation to determine how much potassium bicarbonate to add? We need to do that first in order to lower our PH, which is currently about 7.0. 

Thanks in advance for any help you can provide :)

[Jeff S]

You don't need any special water for germination. Seeds have plenty of nutrient for the initial growth. I do use the system water because it's convenient and I don't have to worry about when to switch over to system water.

I don't think you need a pump for germination. It takes very little water to germinate.If you do use a pump anything special for a pump as long as the pump can overcome the 6' head should be ok. You shouldn't need to much solution flowing. Check out this video for how this guy germinates.  https://www.youtube.com/watch?v=zHyJKp2bgFA

To lower PH just put a little muratic acid in the system, and I mean just a little. It's inexpensive and can be used for lots of other things as you go along. (don't sniff it)

[Darlene Cerullo]

Ok great, that makes sense. Have you ever heard of controlling the kH to stabilize the pH? How often do you normally have to adjust the pH?

[Jeff S]

I've heard of it, I think in one of Sylvia's videos but I have never worried too much about it. I've tested it but didn't make any changes. There are 2 schools of thought for controlling PH, carbonates and hydroxides. Sylvia likes carbonates but I like hydroxides. The hydroxides give you more control especially in larger systems (that includes yours). Nate Story at Bright Agrotech has a great series of videos that are on point and accurate on everything aquaponic. https://www.youtube.com/watch?v=xCKYREoBos8        https://www.youtube.com/watch?v=zP1rUMyklyc&t=78s

[Tom Oliphant]

Dear Darlene,

My understanding is that to encourage beneficial bacteria you need a large particulate swirl filter, a biological filter, and a sump tank. Without that you may be limiting your system's ability to produce nitrates. I have all three and I get over 160 ppm in my hybrid system. I have a 500 gallon fish tank so the filters and sump are indispensable.

TVO >:)