Ive been building my system over the last 4 months since just before xmas 2012. I thought that I had cycled it successfully, but after leaving it alone over Easter I came back and found my ammonia had shot through the roof.
I realise that my understanding of what should have been happening is not complete. Well, Ive always been guilty of simple oversights which tend to come back and bite me in the bum. I wonder if anyone can offer their opinion about what I may have done wrong.
I bought my IBCs from Pat the drum man at Cavan. They had them for $66 dollars each. I got three. The downside was that they had PVA glue in them which needed to be cleaned out. It was not exactly what I had planned for my xmas holidays but progress was slowly made.
I got the main swag of plumbing fittings from Wet Earth. Definitely way cheaper than the big B, which I have been to way way too many times in the last few months. Why don't they have frequent shoppers rewards there???
The water pump turns over a rated 2400 lph. The beds both fill in about 15 minutes and drain in five.
For the media, I wanted to get river pebbles, but couldn't find any (in the two places I visited ) which didn't have limestone. I went with 20mm blue metal instead. I like the color scheme now. Way heavier and way cheaper than anything else. I used a spare 200lt drum of water and another big tub of water as a two stage slurry with a colander and hand washed it by the shovel full. However as a result when I finally turned on the system the water was very clean, no clouding at all.
Finally I assembled the pvc pipes together over two nights and spent another night glueing everything together. I was doing so well. I had just about finished when I spilt the red about 200ml of red primer over one of my media beds. So now I have some pink gravel.
I read about affnans siphon and built two of those. I was also half following some of murrays instructions and the two got intermixed. As a results my stand pipes finished about 50mm beneath the gravel surface. Too much? Anyway, I made another two and now its just over 25mm. Much happier the second time.
I decided to be a patient man and do a fishless cycle. Trying to source some ammonia I read about Urea. Perhaps this was where I have made my first mistake. I'd love to know what others think. My plan was to add two teaspoons per day. I did this for about 3 weeks and started to see predictable signs of nitrates appearing. My Ph started at 8.2 and over the course of the 3 weeks dropped to about 7.8. Water temps all the time were between 28-30 degrees C when I measured each evening. I noticed nitrates appearing 18 days in and also the tanks got a few green blotches and some fine algae (I actually celebrated the signs of life). The ammonia slowly raised itself to about 4ppm.
Twenty six days into the process the nitrites dropped off to zero and similarly did the ammonia (maybe .25ppm). The Nitrates peaked at what I read to be 20ppm (Does anyone else have trouble interpreting the colours? Should I hold the test tube against the card, or away a bit?
Regardless, this is where things get interesting. I went away for 4 days. Before I left I does the urea higher than normal (perhaps 6 teaspoons for the 4 days I would be away). When I came back, the ammonia has gone up to 8ppm. I felt gutted Since then I have done nothing to the system (except add maybe a cup of seasol for the few plants I put in).
Over the Easter break we had a bit of a cold snap here (maybe down to 12deg C) and had some rain showers.
While the weather was hot a few weeks ago I was topping up using tap water which had been sitting in a 200l drum for a minimum of 2-3 days. If the lid was on the 200l would this stop the chlorine from off gassing? Do people test for Chlorine/Chloramine before topping up?
I have reached the end of my understanding as to what could have caused that ammonia spike. It has been eights days since then and there has been no movement of any of my testings.
I hope that even if I killed off the bacteria, with the current burst of warm weather ~27 deg days there is some hope that the system will reboot and start cycling again in another week or so. Is having such a high level of ammonia a really bad thing? I don't really want to start preparing water changes for a 1300L system.
I also have question about air. I bought a hailea ac0-308 which overheated on the first night and shut itself off. I don't know if it was always bad, but now it overheats if I put more than two Haliea 4cm air stones (about the size of a fat 50 cent piece) about 20cms into the water. I accept that I overdrove it myself, so it was my fault. I ordered a resun lp-40 which is supposed to be a deep water pump. How can I tell if i am overworking this pump? I put four airstones (three dropping one meter into the fish tank and the last one into the sump (20 cms) and the water boils like a spa ) I read in one thread somewhere (of course I cant find it again) about making a pvc bridge with a blow off valve. Any recommendations? How do I know ahow many airstones I can use. The pump comes with a 12way splitter! I'd like to get more DO into the water but am nervous about leaving an air pump alone until I know its going to be ok.
Mistakes I know I made:
1. Not spending the money for food grade and cleaned ibcs on day one.
2. Cut stand pipes too short for grow bed -> redo standpipes and bell siphons
3. Spilt red pvc primer over gravel!
4. Cooked my first air pump
5. Killed my bacteria???
6. <just a matter of time>
Finally I want to thank all you contributors who got me into this. Its been an awesome addiction so far.
- nft tubes over fish tank
- diy hoop house for winter.
- battery 12v backup
Thanks in advance for comments, advice for next steps!
my youtube video of the system up and running: