Pumpless water change scheme (1 Viewer)

[merkurmaniac]

So, I have a room that I built upstairs in my attic. Its 14'x10' adn is air conditioned, has a ceiling fan, workbench, wood floors. Well, its become a fish room of sorts, but my tank is downstairs. My rodi set up is upstairs, as are a bunch of chemicals and my ATO tank. I had run a small airline down to the master bathroom that I had valved so that I could get RODI water at the bathtub and mix up my water there. I'd go upstairs and start the water flowing after I had set a 5 gallon bucket in the tub and then go till it overflowed into the whirlpool tub. Then I'd add a pre-measured qty of salt to the 5 gallon bucket that would produce water of the right salinity. I had a pump that would circulate the water inthe bucket overnight. I'd then lug the water in front of my aquarium and use a method whereby a pump that I would drop in my sump would push water into the 5 gallon bucket, which would displace fresh mixed back into the tank. That system has worked well for a long time, but I got sick of having to deal with a poor sealing lid that would occasionally leak water on the tile floor as it was pressurized during the transfer. I was also starting to feel guilty for having so much "fish junk" in our master bathroom tub. So......

What I devised is the following: I put a 5 gallon bucket next to my ato in the attic room. I also rerouted the line that went to the masterbathroom tub to my sump instead. this is where my fresh-mixed water will arrive from. Now, I transfer five gallons from my ato to my 5 gallon bucket and dump in the salt. I then can let it sit for days if I want, as no one goes into that room except me. So, then I made a weighted acrylic piece that just keep the "upstairs" end of my 50' long 1/4" plastic tube at the bottom of the fresh-mixed saltwater bucket. Now, when I want to do a water change, here is what I'll do (did it today for the first time.)

1. Walk up to fish tank with a blue bucket with a nice handle to make carrying off the old saltwater easier. I calibrated it by marking the side at the same level as the bucket of fresh-mixed water (about 5 gallons.) this is my target line. I need to get this much water out of the DT. So, I made up a piece of tubing that will hang over the side of the DT and droop down into my blue "waste" bucket. I can start a siphon on it now. Then, I find the "downstairs" end of my air line in my sump and then I have to apply suction (via mouth) to that line and pull hard enough on it to start water flowing, as there is a "high point" the water has to be pulled up to. Then, this water begins to flow. At this point, there are several hazards or failure modes.

a. Siphon in too much water from upstairs and flood the sump. (I prevent this by only having 5 gallons in the upstairs "fresh-mix" bucket.)
b. Water is added faster than water is removed which causes an overflow condition. The water from upstairs runs at a rate of 1 litre in 2 minutes. I timed how long to fill a 1 litre bottle. As long as water is pulled out by the waste siphon at a faster rate, it wont overflow.
c. Water is pulled out too fast resulting in return pump blowing bubbles and cavitating. (must run the "waste stream" at a only slightly little faster rate than the fresh-mix stream.)
d. Main hazard, too much water into the waste bucket by unattended, endless siphon. (today I ordered a float valve that I plan to mount into my waste bucket to autoshut off the waste stream at the right level.)

I plan to add a needle valve to the waste stream siphon so that I can add a restriction and better tune the flowrate to the target .5 litre per min.

The other bummer is the amount of suction that has to be applied to get the water flowing from upstairs. I plan to elevate the freshmix bucket to a level closer to the high point to make this part easier.

So, I am able to do my water changes using two siphons, as the water was mixed upstairs.

The main thing that I think will be harder will be flow matching the two streams. I can also set a timer on the microwave to about the time the waste stream should finish to be a bit of a backup in the event the float valve does not cut off.

Richard

 

[trb]

Good ideas Richard! Have you considered putting a valve on the new water line at the sump, and then tap into the bottom of the 5 gal bucket upstairs for the inlet? That way you can just use gravity to feed the new water to the tank. Also, I use a small pump attached to a vinyl hose (from my fresh water Python gravel cleaner) to drain my tank. I set it at the right depth in the tank, and it runs until it pumps dry, draining into the sink.

I'm planing something similar on my new tank, since it will be located just 5 feet through the walls from my bathroom faucet. I will have a drain line with a valve on it running from my display tank to the drain at my sink, eliminating any buckets of old salt water. I'm still planning to pump the new water to the tank, but through the wall also. I know it will take longer to fill mine back up than to drain, but I can easily drain up to 25 gallons or so from my system this way.

 

[merkurmaniac]

I don't mind the draining of old water taking a long time. I actually want it to match the input of fresh-mixed, or else my pump will run dry. I also dont mind recovering the old salt water as its a good way to measure how much I take out, which should be right at the amount I put in. Also, I sometimes will use it to rinse new charcoal or some other job where I might use "old" saltwater. During the summer, I dumped the old saltwater at the edge of my slab, as the clay still needed the moisture.

I like the idea whereby the pump runs dry after removing a set amout of water, but for me I am just siphoning with a small tube to get an intentionally slow flowrate. I am also siphoning from my display tank, so its level is not fluctuating. I had just been dropping a pump in my fuge, but I wonder how many little critters were getting thrown out with the bathwater.