My only pak choy on the other hand is growing but the leaves are yellowish. Still a long way to go for me and this project...
Tuesday, 30 October 2012
D.E.A.D Kesum!
My only pak choy on the other hand is growing but the leaves are yellowish. Still a long way to go for me and this project...
Eid-ul-Adha Break
Sunday, 21 October 2012
The Flood and Drain Timing
So last weekend I make the holes a bit bigger and manages to get 4 minutes for flood and drain, about 50 seconds of that is the drain cycle. Not satisfied, I drilled 2 new holes using a 5mm drill bit and the inevitable happened. The syphon action didn't happen and the equilibrium flow is achieved. This is not good. From this experience I learned that to get a positive syphon kicking in every time, the water rate flowing in must ALWAYS be more than the water rate flowing out. Otherwise the water will just flow continuously from the the stand pipe without the syphon action.
I was lucky because my pump has the variable flow setting. So I increased the flow rate to about a quarter and the syphon is back in action again. This time I get 1 minute for drain and 6 minutes for flood, a total of 7 minutes duty cycle. I just leave it at that for now and see how the plants doing in the next couple of weeks.
I also forgot to mention that I sown 4 pak choys and 4 lettuces in a soil in a separate seeding pot last week. The pak choys are already sprouting but not the lettuces. So I did a bit of googling and found that lettuce will have small to no chances at all to grow at temperature above 27 degree Celsius. At 27C, it will flower faster so less leafy. Ideal temperature would be from 22 to 25C. As from my previous post, the ambient temperature around my grow bed at noon is about 34C! So it is not going to happen. I was thinking probably I can grow lettuce inside my house where it is colder or wait for monsoon season where temperature will drop to between 24 to 30C. I'm sceptical that it will grow but I'm going to try anyway when the time is right.
Sorry no picture this time folks!
UPDATE: Last night I heard the water flowing continuously into the fish tank. So I checked it in the morning and found that the water is flowing in equilibrium again. It seems that the water inlet flow rate is slower than before. I don't have time to check why, so I just increased the pump flow rate a bit and the problem is gone. Will check it again tonight.
Sunday, 14 October 2012
Update at 1 Month
First, the fish. I got one dead tilapia on week 2, that is basically it. the remaining fish are extremely healthy, and eat normally. I feed them twice a day. The water is not smelly even if I put my nose really close to the water surface. I think that shows the ammonia level is very low in the water, a condition which we want to achieve in aquaponics.
The plants however is not doing very well. My kesum has yellowish young leaves on week three. This week I realized the young leaves has turned brown and some are dead. This is not good. I don't know what is wrong. My friend suggest the system is not fully mature yet, I think he is right. The fish apparently does not produce enough waste for the plant or the bacteria is not fully colonized the grow bed yet. So there is not enough nitrates for the plant to grow healthily. My pak choy on the other hand...well...only one left. My fault! I have to admit I was too eager to move the pak choy sprout. I should have wait until they are about 2-3 inches high before I move them. I moved them too early (I want to arrange them in the bed) and all has dies except one. The One is showing food deficiency too.
I took a temperature reading on the grow bed. This is not the pebbles' temperature. The pebbles are pretty cold actually because the fish water helps cool it down. The fish water is very chilly! The temperature is ambient, probably the highest temperature for the day (note the time is almost 2pm). My watch also showing rain is coming, it rained cats and dogs at 3pm that day.
This is another modification I made to the pipe. I found that my water pump is too powerful, it can fill my grow bed in about a minute on minimum setting. So I drilled some tiny holes on the pipe near the pump end to release some water pressure and now it took almost 2 minutes to fill the bed. The flood and drain cycle now is about 2.5 minutes. I searched info on ideal cycle timing but I found no concrete evident of a good timing. Most people that use timer flood their bed at least 4 times a day for 15 minutes each. For automatic syphon like mine, most say they don't really care about the timing because frequent flood and drain actually introduce more oxygen for the roots. Also, I only use one pump with no bubbler in the fish tank. I have to keep my pump on 24/7 for the fish. This modification also introduce an underwater current in the tank. The fish like it, they keep swimming in and out of the current, good exercise! the current also helps feed the pump with waste as it moves along clockwise in the tank.
So, I put another month for the system to fully mature. By then the fish would grow bigger and produce more waste, hopefully the plants could get what they want.
Wednesday, 10 October 2012
Pre Filter Part II
I went for a job interview in the afternoon today and came home early. On the way home I kept thinking about the interview, somehow I think I flunked it. So I decided to finish my pre filter just to feel good again.
On my way home I stopped at the hardware shop to get some parts. My friend told me I should use a check valve to avoid the water in the filter from getting back into the tank when the pump is off. It is a one way valve and the hardware shop is selling it for RM20 a piece. Made of brass. I think I'm gonna pass it this time.
I bought a T instead. I replace the elbow in the filter with the T as in the picture below. I turned off the pump and guess what? It worked! The T broke off the syphon pressure and prevent the back flow. For RM1 the problem is solved.
Don't jump for joy yet for this solution is not 100% fool proof. If the filter get clogged, the pressure under the filter will increase causing the water to spill out from the top of the T. I can use this as indication for dirty filter! So when water spilled out I need to do the back flush to clean the filter. Brilliant!
Sunday, 7 October 2012
Prefilter for Grow Bed
I thought building the biofilter is an easy job but it turned out it is not! What was suppose to be an hour job has now turned into half a day job and I'm not even finished yet. There are two problems I'm now currently facing. One is leaking and the other one is the water in the biofilter is syphoned back into the fish tank whenever the water pump is turned off.
I managed to solve the leaking problem, for now. The problem is caused by the 'ribs' at the bottom of the bucket (container) I used for the filter. The ribs are there to provide extra support to the base. I'm sorry I forgot to snap a picture. I'll update that later. So I sanded it down using my vibration sander and it seems that the problem is gone, for now. If it still leaks I would have to seal it with silicon. I'm trying to avoid using silicon for now as it might be bad for the fish.