Backyard Aquaponics
A place to discuss aquaponics

Ok I have been designing and putting together my cold water system

system link
viewtopic.php?f=18&t=3693

as part of the preparation to speed things up I started a small (100L) heated system and bio filter to try and get going earlier in the main system. All went well and I was getting nitrates at about 3 weeks, I was using humonia for dosing and all seemed to be progressing well.

Then all of a sudden my ammonia conversion stopped and my pH was 6 or below, so I figured the low pH was inhibiting my bacteria and I added egg shells. After this pH rose to about 7 and nitrites were appearing again however a few days later I also got a bad smell, ammonia went off the scale and pH went though the floor again.

Deciding that the egg shells were adding too much organic matter I switched over to shell grit but nearly a weak later there is no rise in pH.

I added about a cup of eggshells and about a cup of shellgrit I only have about 100L water.
So how much needs to be added to buffer pH?
Also since I did this I have read that egg shells should be baked before being used, I guess this would carbonize the organic matter and prevent the ammonia surge, would this be right?

Stop peeing, don't need much in that lil system.
Did the first bio crash coincide with a temp drop?
Acidification is a by product of the nitrogen cycle. The second time ur bio was re establishing. Think u will start to get nitrites and nitrates again shortly.
Just less margin for error in a small setup.
Keep the pumping up to consistently move that water thru the bio.
Wouldn't worry too much about the heater. Your bio will get used to that temp and will crash if u inocculate this in a colder system. Let it establish at room temp and it will handle the transition better.
You are prolly closer than you think.
Ell would recommend the 'P' word.

I suspect too that the issue may have been overdosing along with the pH crash. If you can place your shell grit in such a way that your system water is forced through it, it may be more effective. I found that egg shells didn't quite cut it (at lest not the bag full I tried using at first before getting lots of sea shells.)

I also learned that it doesn't take much hummonia to keep a system ticking over. In a system with a fish tank of less than 50 US gallons (189 L), 50-100 ml of hummonia per day is probably all that is needed. My 600 gallon system (2271 L) when it was still only 600 gallons only needed between 200 and 400 ml of hummonia per day for cycling.

You should probably wait till your ammonia readings reach 0 before dosing again and you want to keep the doses small and regular. Kinda like when adding fish to a system keep the feeding low till the system adjusts. keep the doses small till you system can cycle what you add to 0 in a day before you try increasing the dose. And by that I mean both Ammonia and Nitrite should be able to return to 0 in a day.