Backyard Aquaponics
A place to discuss aquaponics

It isn't just nitrates that you're looking for. Anything that contains Nitrogen, like proteins, urea, ammonia - basically these can break down and be converted into Nitrates so they could be the source of the nitrates that you found (may not be either though )

Urea - CH4N2O
Ammonia - NH4
Proteins - tons of different ones. Amino groups contain nitrogen

pH 8.2
Ammonia .5
Nitrites 0
Nitrates 10

How many bullhead catfish do you have in the system and are you feeding them at this point? If you are feeding hold off feeding for a day or two and see if the ammonia comes down. Bullhead are durable but no point in keeping the ammonia high. I'm not sure of your water temperature and the toxicity of Ammonia is affected by this as well as pH. There's a table on this page that lets you see at what level the ammonia becomes toxic (based on pH and temp) - http://ibcofaquaponics.com/information/tables-and-charts/

It looks like you have a working biofilter although it's not fully able to take care of all the ammonia you have at this point (it is keeping up with what's being produced though).

If you haven't you should add some plants into the growbed, they'll help use the Nitrates.

There's also a good read called the IBC's of Aquaponics available in PDF format that's a freebie - http://ibcofaquaponics.com/ - It might be of use if you haven't seen it and includes the charts and tables.

I only have 5 bullheads and am running 175 gallons, maybe a bit more. Ammonia has been consistent but I will not feed any for a few days and see what happens. I didn't realize that .5 was high since I haven't ever gotten it to go above that. The nitrates are hard to read as to the actual level so I am making my best guess. They are definitely there though.

I don't have a thermometer in the tank, but I would guess the water to be at 50-60F or 12-15C. Plants are being added tonight and tomorrow and I am building a greenhouse over the grow bed to try to get more heat into the bed and plants since we are not to consistent warm weather yet. We will get into the low 70's some days and still have nights in the 30's. Today we barely made it to 50F.

I did read the IBC guide, at least parts of it. I'll take a look at more of it to see how it applies to my current stage.

Thanks for the post!

Sounds like a good plan as far as holding off on the feed and getting everything moving along. I am going to also suggest that you salt the tank water as follows for protection from Nitrites and stress relief for the fish (Helps them with their slime coat) -

Nitrite issues - 1ppt = 1KG per 1000L or 1gm per L - use un-iodized salt (NaCl) without any caking agents. Pool salt usually is good and sometimes you can buy sea salt in the bulk bins this way at the store. There are other sources, I just can't remember them at the moment.

You aren't currently showing any Nitrite but the Ammonia is being converted to Nitrite before it goes to Nitrate. Basically I suggesting it as a precaution because it's not uncommon for there to be hiccups in the process at this stage and it's cheap insurance.

If you're planning on having Strawberries in this bed then I wouldn't salt. They seem to be more sensitive than most plants.

Cheers

I would prefer not to salt as we are putting strawberries in the bed. Bullheads are pretty darn sturdy fish so I am not too worried about them. That being said I will watch the numbers and adjust my thoughts accordingly.

I appreciate your feedback and pointing me in some good directions.

Water temp 48 degrees so I know that will slow down the bacteria growth. Hopefully, the addition of a green house over the grow bed will help get more heat into the water and media until our temps get warmer.

I didn't put a hole at the bottom of my standpipe. I'm using a bell siphon. Do I need a hole at the bottom?

I run two pumps so if a pump were to fail it should still run, at least as constant flood. We live in town where power outages are pretty rare and usually only last for an hour or two. My fish are catfish that can handle low oxygen levels. Not sure how well the plants would like sitting in water for a couple of hours.

If your sump (or fish tank, whichever the beds drain to) is large enough to hold the water from the grow beds should the power go off, then having a hole in the standpipe is a good thing. The only systems that don't use the hole in the standpipe should be Constant Flood because normally the sump is too small in these systems so you want the water to stay in the grow bed.

Leave the standpipe removeable then you can flip it so the hole is up if you decide to try out CF

Edit: Forgot to mention, it's also OK having the hole in the standpipe for CF, if the sump/FT is large enough to hold all the water.

I'll have to pull the standpipe and drill a hole in it. It takes some work but I can get it out or change the length to adjust water depth.

I got the bed planted today. Also got a small greenhouse to enclose it for the next few weeks until temps warm up enough and the threat of freeze is over.

pH 8.2
Ammonia 1
Nitrites 0
Nitrates 20
Water temp 50

I honestly have a hard time determining if Ammonia is .5 or 1. I did plant yesterday and though I rinsed the roots as best I could, I am sure some remnants of whatever they were planted in entered the tank. I haven't fed the last couple of days as I am looking for the Ammonia to come down before I do.

Nitrates. The colors on the chart look the same for 10 and 20 so I am guessing which one it is.

I made a cover for the top of the tank opening to keep light out and wrapped the fish tank in a blue tarp to keep the light off of the water. Next weekend I will fashion a permanent surround out of either wood or corrugated tin roofing.

I didn't set up the greenhouse as we are going to be close to 80F this week and I won't be home to keep an eye on temps and open or close it as appropriate. No expected frost or freeze this week either.

Was gone all week in Texas and then Alaska. Came home to the tank working fine, no algae, all fish alive and accounted for and crappy looking plants.

pH 8.2
Ammonia 1
Nitrite .25 I think
Nitrate 20
Water temp 62F

The ammonia doesn't move much even though the fish weren't fed all week. I think I'll pull the hide pipes out and get rid of any stuff hanging on the bottom of the tank.

I did do a foliar application of maxicrop plus iron as the water is likely deficient and the pH is likely causing some issues with uptake.

I the siphon was working fine so I fiddled with it. Now it's not working fine. Should have left it alone.

Some of the plants look better with some applications of foliar maxicrop plus iron. Asparagus are sprouting which is cool. Nothing else showing from seed. Transplanted vines look the worst but some new growth coming so hopefully it was just the shock of the transplant.

pH 8.2
Ammonia 2
Nitrate .25
Nitrate 10

I fed the fish when I got home from Alaska and the ammonia went up to 2 and has been there the last couple of days without any additional feed. I know catfish put off more excrement so that may be what is keeping it up. Kind of surprised I don't get any spiking after a feed.

The siphon is working well, but I am about to mess with the flow rates a bit so we will see how well it stays working when I increase the flow rates a bit. I am getting an 18 minute cycle time and I would rather have it at 15 minutes which means I need to speed the flow rate up of water going into the bed. The siphon starts and breaks great right now, I just need the bed to fill faster.

Sounds like you're doing alright SB, just keep watching the Ammonia and Nitrites and hold the feed when they're too high (based on the toxicity chart for ammonia anyway). Eventually you'll get more stability in the system and you won't have to watch it as much.

Cheers

Nothing much has changed. The water is really clear. I got a lot of maple seeds blown into my growbed and tank. Picked as many as I could out of the growbed and scooped the fish tank clean to get that material out and prevent additional nitrates. I haven't fed in almost a week and the ammonia is staying stable at 2. It's just sitting there. Not sure what continues to add the ammonia to the system or if it is just that the nitrification process hasn't really gotten going. I have some buckets set up to catch rain so if we get some good rain tonight I am going to do a small water swap based on how much rain water I get. At most it would be 5% but it would at least get rid of some of the ammonia.

The plants are not growing much, but there is some new growth. It's still a bit cool here most days so we are not into prime growing season yet. I am doing foliar applications of maxicrop plus iron.

pH 8.2
Ammonia 2
Nitrates 1
Nitrites 20
Water temp 58f