Backyard Aquaponics
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Nitrites still up around .5..maybe a tad higher.

Fed lightly, dosed...wait. repeat.

Thanks Coach!

Nitrites are still a little above .5. I fed very lightly, dosed a few more ounces of sodium bicarb, and turned on the loop that added from the sump back into the shade cloth filter. I had to adjust a few ball valves on the FT's, but not too bad. Not sure if this was a good idea, or if i should just continue to wait it out. Honestly, I'm tired of waiting. I think it's been 7 weeks now, and still having to feed the fish 1/10 of what I would like to feed them.

We'll see if this makes any difference. All I'm doing is taking water from the sump and pumping it back through the filters again. It will increase(double) retention time of that amount of water, but will also slightly decrease the retention time of the rest of the system due to the additional water flow into the shade cloth/netting filter, which then supplies the mbbr. At this point, I feel it can't do much harm. Worst case, I stop feeding and do some more water changes...deja vue.

Same song, different verse. PH in system-7.6, PH coming out of MBBR-7.5, water temp-83, KH- 143.00, ammonia- 0
fed lightly this am.- a little over 8 oz. dosed with a few ounces bicarb. nitrites around .5

This afternoon(5:30)- everything about the same, fed about 12 oz, dosed with a few more oz. bicarb, nitrites still around .5, maybe slightly higher.

I added a little more air to mbbr. I was going back over notes, and when I started cycling with my homemade bio-balls, I added more air then I'm running now. Do I ever need to clean the mbbr? I scoop out a few cups every so often and look at the water, and it looks very clear. When I shut down the air, and drain the bottom drain in the mbbr, there is no debris.

I haven't cleaned my small MBBR in close to a year.. Not sure what everyone else is doing. I would keep that air going in that MBBR and never shut it off. Perhaps if anything.. Clean out the shade cloth more often. I know Paul runs his home system completely without any polishing filter. Just fish tank RFS to MBBR to sump. What does Ryan think?

I haven't been keeping track of things here but do you have an oxygen meter?

Swede, when I do shut the air off, it's only for a few minutes, and only when the pumps are on a water is flowing from the shade cloth/netting filter. I haven't talked to Ryan since he returned from his vacation in Europe.

Stu, yes I have an O2 meter. I haven't checked in a while, but was around 6-8 last time I checked.

When the sun comes up here, I'll check again and clean the shade cloth filter again.

Perhaps check DOof water coming in and out of shade cloth tank before cleaning it,

I was wondering if I was the only one awake at 4:00 in the AM

Shade cloth filter, don't they go anaerobic being bad for fish and plants?

Cleaned shade cloth/netting filter. Also took some readings after. Kind of strange, and don't understand.
Filter wasn't that dirty. I haven't been feeding much, so this makes sense.

Nitrites were a little over .5 this AM. No feed. KH was good, no dose.
Before cleaning shade cloth filter PH was around 7.6 in RFF and about the same in mbbr...indicating not much bacterial activity?

After cleaning, nitrites in mbbr down to zero, PH UP to over 7.9?? In system still 7.6.

It take about 80-90 minutes to clean filter. Air is going the whole time, and there is no water entering or existing the mbbr. Did the bacteria consume all the ammonia and convert all the nitrites and then the PH rose?
I didn't check NiTRATES, which may have helped.

O2 is still over 6 in all tanks. over 9 in MBBR.

While pump was off, the nitrites in FT's dropped to under .5, this was with no circulation, just air. No feed this AM again.
I fed lightly after cleaning, and will check again later.

Any suggestions on what is happening?

Boiling the MBBR too rapidly? What oxygen meter do you use? I need to get one soon.

Thanks!

Eddie

Coach,
I think that the shade cloth is causing your problems.. It's getting solids accumulation, those solids starts to break down and they produce ammonia.

The pH going up may be due to CO2 being off gassed in MBBR more effectively once the shade cloth is cleaned and doesn't produce as much CO2.

I may be completely off here on the chemical theory..

But I have noticed that everytime you have cleaned out your shade cloth you reported that Nitrites seem to drop.. Perhaps you should just run the IBC without the shade cloth completely and very very very carefully feed your fish to see if the one MBBR keeps up with it? You may also be able to add any extra MB3 media that you have to the now empty shade cloth IBC and just add air and voila you now have 2 MBBR which will increase your retention time two fold. (just a crazy idea)

What do you think?

Have zero ammonia. I've checked in FT's and filters.
Prior to getting the K1, I was letting the shade cloth filter go 2-3 weeks between feeding, and had very low nitrites?
At that time, I was feeding significantly more then I am now.

The nitrites drop in the mbbr, because the same 250 gallons sits there for 90 minutes. My concern was, why did the PH rise in the MBBR after this happened?

I could do an upwelling K1 like Ryan showed us, but it works much better with a cone bottom and not an IBC.

On your O2 measurements.. What is your current water temperature?
I have a suspicion that your DO meter may need to be recalibrated. This chart will explain maximum DO in relation to temperature and elevation 760 mm hg being at sea level..
http://ua.dnr.wi.gov/regulations/labcer ... _Table.pdf