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Yet another day gone and AT LAST there is water. Nothing every goes as easy as it looks.
This days work started a month ago with diagrams and elevations and planning. I redid the plan at least 3 times. First a Two Pump system with dump tanks, then a two pump system on timers and floats, then a single pump system with bell siphons and pump in the sump.
At first I considered Trout and would have needed a chiller plumbed in-line. Research showed chillers for my system would have been $1000-1300 and expensive electricity to operate and the cooler temperatures of trout would limit the kinds of plants I could raise. So I decided on warm water fish and needed a heater for winter. I bought a new 40 Gallon (150 liter) propane fired residential water heater for the job. Next I was concerned about toxic metals and fittings. After much research, here is what I concluded:
PVC, Plastic, ABS, Stainless Steel, Aluminum, Glass, coated steel are all ok.
Galvanized, Copper, Zinc, and regular steel all bad.
The Water heater has coated steel inlet and outlets. The drop tube is plastic, the drain and overpressure appeared to be Galvanized and Copper (bad). I replaced the drain with a stainless steel nipple and shutoff valve (ball valve). The pressure valve I left as I have not found a replacement. I hope its such a small part that it will be ok. The Ball valve was recommended to me by a plumber who said a ball valve allows large particles to be flushed out of the tank, where as the standard faucet tap fitting is very narrow. Also the anode in old water heaters is ZINC which guarantees fish kills, but the new water heaters have a Magnesium anode, which is used by plants. (Subsequent water tests showed no elevated levels of toxic metals.) Also the tanks are steel, but glass lined, so safe. All connections, adapters, and flex tubing is either PVC, plastic or rubber. Essentially, a galvanized, copper free system except the overpressure valve, and Im betting the outlet nipple is coated.
The greenhouse already had the propane plumbed for the space heater. I ran the exhaust vent up and out the end wall that backs the water heater. I put the whole thing in a drain pan over some solid support, just to keep the heater off the floor and to prevent imbalance due to settling.
I also finished burying the sump tank. Originally I had planned to leave it sticking up above ground level 8 as there should have been enough elevation drop for the drain pipe. But when I fitted the 3 ABS (75mm) black sewer pipe with Y fittings for each siphon drain and connected the bell siphon outlets, it wasnt going to work. So I dropped the sump tank all the way to ground level. Then for the drain pipe out of the siphons, I used flex tubing, which allowed me to have the flex rise slightly before dropping into the Y drain fitting.
On my first test of the siphons, they wouldnt hold siphon and would break before the water level had dropped ½ way done. First I had to much head space, which I fixed. I made sure the break tube connections was silicone sealed, and I made the flex drain tube longer so it shoved down inside the ABS Y fitting, giving it more distance to pull from. Then the siphons started working like a charm.
I cycled the beds each 2 or 3 times to make sure the dust and fines were really out. I rigged a hose fitting after the pump so I could flush this water out of the system. Then I rigged the main sump return line 1 ¼ (about 30mm) and ran it along the floor, behind the beds, behind the fish tank to the water heater. There I ran it up and reduced it down to 1 (25mm) with a bypass rigged to go around the water heater if needed. Then it necks down to the ¾ (18mm) going into the water heater, connected by 2 reinforced rubber flex tubes. Then, another flex tube coming out of the water heater and up to 1 and over and into the tank (see the picture). This entire pipe is glued with shut offs and unions so it can be cleaned out.
Next I cut a hole for a 2 bulkhead fitting as high as I could on the side of the tank, wanting as much water as possible in the tank (mistake). I ran 2 pipe out of the tank, across the back side of the beds, with Tees going down to 1 ball valves, dumping straight into the corner of each bed, stubbed out on the end for the DWC bed when its done. When filled, the fish tank was within 1 (25 mm) of the top, way to close for me. I cut another hole just below the last, now the water is about 4-5 (100-125mm) below the top.
Then we started the pump and began filling the tanks for real. One thing I found was that going down to the ¾ (18mm) pipe in and out of the water heater reduces the flow substantially, maybe by 50%. I havent measured it and as I oversized the pump to begin with, I think I will still get a full water change per hour, but beware; rated flow is in full size pipe, no obstructions. (I later upsized the pump as the flow was not enough.)
Once full, one bed cycles every 15 minutes, the other cycles every 20 min. I fired up the water heater as the water out of the tap is 44 degrees (6 C). The water heater quickly raises the temp to 60 degrees (16 C). Ill check in the morning and see how its doing. The temperature regulation will be a little guesswork.
I tested the water after the system had been running for a few hours. 44 degrees (6 C), 0 nitrates, 0 nitrites, 0 ammonia, PH 7.2, TDS 320, water hardness 300+, no chlorine. The PH reading is suspect as the test strip continues to change colors, I read it at 30 seconds as instructed, so hopefully thats trustworthy.
Another day off work this hobby is time consuming.
Pictures are:
1) Full tank, (notice the extra bulk head fitting live and learn, and the water heater connections)
2) Grow Beds filling.
3) Siphon base notice flex tubing curves up slightly, really helped the siphon.
4) Sump tank Although the pics are in the dark, notice you can see the pump in the bottom, nice clear water.
The outlet of the fish tank draws from the bottom of the tank. At the bulk head fitting I have a Tee fitting, with a down tube, then an elbow on the bottom and short stub that is capped. The stub is drilled with lots of 1/2 holes. It has to have the open Tee on top or it would start siphoning and empty the tank. This seems to suck the solids off the bottom which will empty into the grow beds and break down. I also planned on a few Red Claw Crayfish to keep the bottom cleaned up.
The water heater is going to be a little tricky. I'm getting 2-3C temp swing and I had hoped I could keep it nearly an even temperature. I'll have to work on that. (As you will see in later posts, I later installed a sprinkler valve and temperature controller.)
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