Backyard Aquaponics
A place to discuss aquaponics

Just getting my first system cycled (fishless method).

My system currently consists of a 300g Rubbermaid FT (in-ground), in-ground plumbing, (3) 4'x6'x1' media beds with expanded blue shale, bell siphons, 1000gph pumps, tank heater, and a 70lph air pump. No sump. System pulls roughly 60g from fish tank at once. Swirl filter, FT cover, lattice work and fish are soon to come!

3 weeks ago I didn't know what the term "Aquaponics" meant. I guess I have the bug?

I have attached a picture of my beds when first filled with media. Is it allowed to post a Google Drive link to share pictures, rather than resizing them all?

Best,
Andrew

Re-sized more..

A few more. Should cover the basic idea of what I have going.

FT pumps into top bed, Bell Siphon (and an emergency overflow) drain into bed #2, then #3, then #3 returns underground to FT.

Ive been dosing ammonia daily to 3-4ppm for about 5 days. I used Nite Out II to kick system off on day #1. Nitrites have been around since day 5, and now- day 7 nitrates are showing up. I today is the last day that I will dose ammonia. Avg water temp is 68.

Supplemented with Maxicrop.

Thoughts, recommendations, concerns?

Best,
Andrew

Good job with your AP build Andrew

Thanks Scotty.

This design (beds flowing from one to the next) isn't popular. Is there a worry that bed#1 will get more noots than bed#2/#3?

It was the only design that allowed for a decent amount of bed space without having a)huge FT b)sump c)both.

The tank turns over almost exactly 1x/hr. I plan on stocking Mozambique Tilapia once cycle completes. Exactly 2 cubic yards (1500l) of media, with 375 gallons of water in system- thoughts on stocking numbers? 75-100?

The FT never has less than about 250 gallons.

Best,
Andrew

You might find that nutrient levels are lower further down the cascade. I can't see this being a huge problem though. A larger problem might be the accumulation of settleable solids in the first bed but just keep your eyes open for that possibility. It would be simple to add a solids filter before the first grow bed in your system so just cross that bridge when you come to it

If you don't like the way it's working out (but I think you will ) just loose the siphons and switch everything over to Constant Flood and the sump size becomes almost a non issue.

Today's water test. This is day #7 since (d-klor'inated city water) was put into system. I also used Microbe Lift Nite Out II to kick cycle off. Water temps still average about 70-72.

What should I do about ammonia? I have been dosing up to 4ppm daily, but have read that I should cut back so second set of bacteria is not inhibited. What's my target ammonia ppm until cycle completes? System is now consuming 3ppm ammonia in 24hrs. Nitrates have been gradually gaining momentum, but I don't expect them to spike since I already have beds fully planted.

ph: 7.8 (maybe a little less)
Ammonia: 1ppm
Nitrite: off the scale
Nitrate: somewhere between 5-10ppm

Don't add more, just wait and test from here on. The ammonia should drop to zero along with the nitrites. The Nitrates may as well because of the plants using them up. Once the ammonia and nitrites read zero you can add the fish but keep testing for a few days because ammonia and nitrite spikes aren't that uncommon in systems when you add a fish to the system. If they aren't eating at first you'll also want to watch the levels when they start eating more . Stop feeding if you get a spike. Water temp and pH will give you the information you need to determine if the ammonia is in the toxic form (see table here - http://ibcofaquaponics.com/information/tables-and-charts/). For nitrites use un-iodized sodium chloride that doesn't have any caking agents added - here is the amount needed - Nitrite issues - 1ppt = 1KG per 1000L or 1gm per L

Ph drops with rain, and steadily climbs back up to 8.0+. Should I fight that with hcl, or just let it be? I'm worried about locking nutrients from plants. Tested my shale- its completely neutral. How long should it take to defeat the buffer capacity of my city water?

First off, awesome job building the beds!

I wouldn't worry about the lack of nuts in the last bed, it'll be fine.

My pH was around 8 for over a year, as long as the ammonia isn't too high, it'll be fine.

The higher pH water can be an advantage down the path when you've got a higher fish load, you won't need to buffer up the pH constantly like a lot of people do. I'd just leave it for now.

I've been curious about how well the siphons work in the cascaded beds like that. Do they all kick off in a row, or is it scattered?

Thanks for the help and reassurance guys. I appreciate it.

Colum- Thanks. I like to over build projects.

As to siphons in cascade- I couldn't be happier. A 1000/gph (3800lph) pump discharges into bed #1 (the one that requires scaffolding to reach), filling it in about 8 minutes (its dialed back 50%). Siphon #1 fires, discharges into bed#2. Since it take 4 minutes to drain, the pump has added 24 gallons of water to bed #1. This "extra" volume of water reassures me that the siphon #2 will kick off. Bed #3 required 2 siphons. With pvc trenched about 50 feet, it had a little too much resistance to handle siphon #2 and not overflow. I was glad I ran the extra line, just in case. Bed #3 has (3) 1"pvc lines as drains- 2 siphons and 1 emergency overflow. It's never needed the overflow.

Sequence goes like this:
bed#1 siphon start
bed#2 siphon start
bed#1 siphon stop
bed#3 siphons start
bed#2 siphon stop
bed#3 siphons stop
brief rest
bed#1 siphon start...

It's very systematic and predictable. Never scattered.

I am flooding and draining faster than I would like to, (5x/hr) in order to turn over FT every hour. I plan on having another set of beds identical and parallel to these (its already plumbed), once the old fence comes down. At that point, I should be able to slow my flow by 50%.

I guess it's obvious, but the best part about the cascading design is the avg volume in FT. I allow bed#1 siphon to start and then turn off the pump. This drains everything except the bottom 2" in all beds. I've been topping FT off from there. My min FT volume is over 80% of total volume. Its great.. so far anyway.

Anxious for fish!!

Best,
Andrew

Not that I have anything against over engineering, but how come you didn't just build one long bed?

One long bed (same volume as 3 combined) would've removed more water from my FT at one time than I wanted. It could've worked, but I would (at times) only have the FT at 50%. I also believe that it will be neat (almost a water feature aspect) of having two beds alternating cascade sequences via an indexing valve. One large bed also wouldn't have allowed for any additional beds, again, with no sump.

It was more work to make 3 instead of 1, but I believe it will keep my fish happier.

Once I get it trimmed out and pretty (top cap and "skirting" to come), I'll make a video for a better idea of its functionality.

Ammonia is down to 0.0 or maybe a tinge of green (<.25ppm). Nitrates up to 20ppm. Nitrites still off of chart. How long should it take for nitrates to drop? Should I go indefinitely without adding ammonia from here? I'm worried I will starve first set of bacteria if it stays at 0ppm ammonia too long. Valid concern?

I dosed iron and trace elements yesterday. Eggplants still showing yellowing. Everything else is content.

Looks like you put some thought into it before building, looks great. What did you use for grow bed liner ?