Backyard Aquaponics
A place to discuss aquaponics

Darn those Koi, hadn't thought about them. I think you'll probably top out around 8 or 8.2 but we'll see.

Yeah, they are proving to be tough. Just fancy damn carp...but expensive.

I hope it's lower then that. I've had tilapia in Nitrites as high as 4-5, and it didn't phase them. probably not good for them, but they showed no ill effects and were eating and acting normal.

Yes, please learn from my mistakes...Lord knows I've made enough of them.

If you do get to 8 or slightly over, like around 8.2 watch out for a faster pH swing upward. I'd be tempted to see if the alkalinity is over 100 mg/L and just call it good at around 8 or very slightly above but maybe Ryan has some ideas.

Update- added another 12 oz. baking soda to system. Trying to slowly get to the 150 ppm that Ryan recommended. I was at around 6 drops...need to get to 8-9 drops 150ppt. I'll keep adding slowly. PH is staying pretty steady around 7.6. Nitrites are still creeping up. I fed tilapia again. A little heavier. I was worried about small ones not getting any food. If they get too weak, the bigger ones will beat them up and kill them.

If I need to, I'll dump more water. Even if I have to dump 1000 gallons a week, I'm using about 1/38th of what I was using DAILY when I was growing nursery stock. Not that I want to do that, but it's still not much water. The guy who I bought my tilapia from drains that much water to his system DAILY. I'm trying very hard to do a zero discharge, but I'm not going to let my fish die from being pig headed.

Ah, Thanks. I did Not know this was a strict RAS I thought it was decoupled AP.. Gets confusing following all these different builds

Coach,
Sorry to hear you are still having problems.. Now when you measure you do use the specific KH test I assume?

Not sure what effect slowing down the flow through the shade cloth bin will have. Also curious how you can slow down the flow without affecting the turnover in the fish tanks?

It's indeed an interesting thread. I have said this before; I think an excel sheet with the build specs in the beginning of every thread like this would be helpful. Helpful to everyone Trying to learn and for those trying to help.

..
KOI... in Australia there is a Koi Code of ethics and true growers are required to cull the more bland babies, so as to preserve the exotic nature of the rest..

I bought 100 tiny CULL for 30 bucks.. they are growing well, except for those grabbed by yabbies and eaten..

They were supposed to be used as fish food..
..
.

Yeah, Ryan was telling me that some growers will brag about killing 30,000 fish to get the 2 "perfect specimens".

I have spread sheets for tracking my recruiting business. Athletes, 1900 schools, 36,000 coaches, offers, times that video are viewed, etc. Didn't really want to so an Excel for this. It ceases to be fun, when I have to enter that much data.
On the flip side, it ceases to be fun when I have to keep screwing with the system multiple times per day to try and control something that I though was under control 5 months ago, and then again 2 weeks ago.

Kh went down after a few hours to 5 drops again. Too tired to remember the number. Just remember I need 8-9 drops, and I'm not close. This after adding close to a pound of baking soda. PH was a bit higher at 7.65, and Nitrites still creeping up. Will need to buy more salt again and it looks like more water changes if I can't get the Nitrites to drop on their own.

Not sure what effect slowing the flow down in the shade cloth filter will do, but it's the only way I can slow down the flow in the mbbr. The shade cloth/netting filter flows directly into the mbbr. The outflow is separate and plumbed from the sump to each tank. As long as I have enough water to the sump to keep up with the pump, I can cut back the RFF knife valves and slow down the flow a bit. The side discharges, which were originally supposed to carry relatively clean water, go directly to the shade cloth/netting filter and do not have any valves on them.

The 150ppm of alkalinity looks like it's going to take quite a bit more. As it runs through the system, it seems to be buffering out? Hoping the nitrifying bacteria fairy will visit tonight, as this is starting to wear on me. I'm about to drain the thing down 50% and start over.

News, but none good. Nitrites up over 1. PH is system up to 7.77, coming out of mbbr is 7.6.
Changing more water out?

So after slowing down the flow you get a higher nitrite reading?

This may sound counter productive and i am not sure it's a good idea. But have you tried to put some air in your shade cloth filter? I had this problem when I used a submerged media for biofilter. I didn't have air and I had high readings of nitrites. As soon as I added air the conversion from nitrites to nitrates happened over night.

Coach in the comment above you tested KH and it's at 71.6 GH/KH... This is confusing to me.. Are you testing KH or GH? They are two different tests. If you are using a GH test and reading is 71.6mg/L that doesn't necessarily mean that your KH is the same.. So are you using a KH or GH test?

Sorry if I am being a pain.. Perhaps I am just misunderstanding your post and you are using the correct KH test..

Coach,
I went back and reread posts to get a better understanding of your system.
- Total volume 6000 gallon
- 1 IBC (275 Gallons) effective water volume 250 gallons? MBBR started August 4th and has received additions of MB3 media from then up until now.. Total media volume purchased 25 cu/ft. 25 cu/ft is 187 gallons.
- 1 IBC (275 Gallons) effective water volume 250 gallons? shade cloth filter, gets cleaned once a week.

So if you are using a 275 gallon IBC with a water volume of 250 then maximum volume of media in there should be 60% although 70% is possible it reduces the mixing capability.. So between 150-170 gallons of biomedia is ok for a 250 gallon container. 150 gallon being the safer bet.

I also just reread how long it takes for a biofilter to fully cycle.. I need to apologize for telling you it would cycle in 3-4 weeks. It can actually take as long as 42 days according to article by Dr Timmons and Ebeling. See this paper page 8. And with you adding new biomedia over this time span from Aug 4th to now We still haven't reached the 42 days for the very first media to have cycled 100%.

http://ag.arizona.edu/azaqua/ista/ISTA7 ... erview.pdf

So I guess we still need a little more patience

longer if there isn't enough food to build bacterial cells - keep at it with the alkalinity (Kh)

Also when doing water changes perhaps pre-treat the added water with bicarbonate if needed.. (test KH of source water)