Tom, Greg, both of you mentioned you have used an automated drain and refill for your tanks- could you give me some pointers on equipment and technique? This bucket brigade is really getting old!

I was wonderin about this as well... Things like regulating temp, so your fish dont die, etc.

Over time, I've used quite a few different methods ... you really have to find a solution that works in your location ... and what type of equipment you have (for example, a drilled tank) ...

Drilled Tanks:
For example, I will never again every buy a tank that is not drilled ... a drilled tank provides an automated drain function .... so no matter how much water you add to your aquarium ... that amount will automatically flow out of the tank ... its easy then to put a pump on a timer that will automatically run for 15-30 minutes a day if you want to add conditioned water to your aquarium from a sump or water barrel ...

I personally used an irrigation timmer hooked directly up to a cold water faucet ... these are getting pretty cheap at your local garden supply ... the water flow in this setup is slow enough that a 10-20% water change doesn't make a significant temperature difference, and I don't personally worry about water conditioners ...

Non-Drilled Tanks
My 180 gallon aquarium in my office is not drilled (I won't make that mistake again) ... when I was in my old office, I had a siphon tube that automatically siphoned water out of the tank on a continuous basis ... I also had a Jehmco float valve that was connected to a small rio pump in a 50 gallon plastic barrel that I used as a water source ... if the siphon got broken, the float valve would automatically shut off the rio pump so the aquarium wouldn't overflow ... the siphon tube had a small hole drilled in it a couple of inches below the water surface, so if I was out of town and my 50 gallon barrel ran out of water, the siphon would automatically be broken and it would not drain any more water ...

Right now .... I'm back to semi-manual water changes on my 180 gallon ... I have a 30 foot plastic hose (same kind I use on my Magnum Pro 350 filter) with a quick disconnect valve on one end, and a faucet adapter on the other end ... I'm only doing weekly water changes now on that tank ... so when I want to do a water change, I turn off my Magnum canister filter, disconnect the output quick disconnect valve on the filter ... connect my hose, put the other end of the hose in the drain, turn on the canister filter, and in about 15 -20 minutes (depending upon how dirty the filter is), the aquarium is about half empty ... I then turn off the canister filter ... connect the disconnect end of my hose to the filter hose into the aquarium ... connect the other end of the hose to my faucet ... turn on the faucet ... and in about 20 minutes, the aquarium is full again ... and I just changed 100 gallons in about 40 minutes while answering email ...

Greg

An automated system has been of interest to me, but in my apartment, I don't have too many options and a 50gal drum would be unsightly. I never realized it but I have the option to do what Greg is doing. I have two canisters as part of my Ocean Clear system. These are already engineered to be drained with a hose as both have a drain valve with a hose thread fitting. I never thought about closing the exit flow from the first filter and turning the pump on, that would make sense. I still like to use a buck to siphon some debris from the bottom ot the tank but I just don't let the 10gal bucket fill too high so it becomes too burdensome. Refilling with the same hose, I continue to siphon, prune, clean the inner panes so that I'm done by the time the tank has filled.

I am contemplating my next big BIG tank, either in my apartment or house, within the next year or so. If I had my own place....the things I could create!

So where exactly is it drilled, bottom or nearer the top?

I imagine towards the bottom somewhere, don't you? Maybe a couple inches
above the substrate

Bill

No, i would expect the drain would be near the top to stop the tank from overflowing, and the fill to be located at the other end of the tank. At least that is the design of all the automated systems that i have seen here in fishrooms and at Aquarium Industries (one of our biggest fish dealers in Australia), all their tansk are drilled at both ends. one end to allow water in and one at a set height to drain water out.

Yep, sounds reasonable to me. If you're using a meridian-style water changer, where it clips on to one of the sides to spray a mist into the tank
(which supposedly and concomitantly blows off the chlorine) you don't need any holes drilled since there's a siphon tube that drains off water (into a garbage can on rollers ) while it's filling. This would be good for "stand-alone" tanks that were unfortunately not drilled in the first place.

Bill

Most of my tanks are drilled in the bottom ... so you use a stand pipe to regulate how high the water level is supposed to be ... as the water level rises, it flows into the stand pipe ...

However ... there are a lot of "homemade" drilled tanks that drill the sides of the tank (usually near the top) ... most of these use a 90 degree elbow attached to the bulkhead to regulate the water height ... I'm slowly working on a fish room and am considering this option because its cheaper to buy used aquariums and drill them myself ...

[A lot of new aquariums have tempered glass in the bottoms which you can not drill yourself] ...

Greg

Alan is one of the folks that did a number for the Discus tanks of some of the local members here.

It uses a timer and slowly drains and fills.
The set up uses a small polypropylene semi rigid tubing for the drain and fill.
This allows a slow water change from a sump.

A float switch fills the water and the timer drains it.

A simple Python styled water changer DIY or you can buy from them is a simple way to remove any bucket work.

I use hard plumbed PVC for most of the fill and drain things.
I turn a knob, I drain, I turn another, I fill.

My client tanks are all set up this way. Takes me 40 minutes to drain and fill 200+ galllons of water with out ever touch a bucket or a hose.

I'll post more on this later.

Regards,
Tom Barr

I've also been thinking about doing a continuous water change method, based on diavolume methodology, concentration and diafiltration technology we use in biotech. While lowering the tank volume isn't a concentration step, I was thinking about doing a continuous removal of tank water and addition of fresh water for a certain length of time, which isn't diafiltration because there is no sermi-permeable membrane, it's more of a continuous dilution, that's it. Does anyone know the formula for calculating a continuous dilution, which approaches 100% over time? Don't know if this would be any more beneficial than a 50% water change, but I could approach a higher percentage without having to drain most the tank. I can do this with an additional hose, perhaps I'll even get my first Python! Ideas? Comments? Formula?