banderbe

If you get an RO unit the issue of using Prime goes away plus you get all the many benefits of RO water. I love my RO unit. Best purchase ever.

BryceM

Hoppy,

Just a thought.... I suspect that a slow, steady drip of water wouldn't supply enough chlorine or chloramine to hurt anything. Concentrations just wouldn't be that high and I think your plants would easily accomodate the difference. Who knows, you might even invent the magic cure for algae. (but I doubt it). You might try it for a while to see if I'm right before adding nice plants & fish.

Don't forget about evaporation. You need to add enough water so that your outflow gets a significant quantitiy of water. Otherwise you'll see TDS creeping upwards over time.

I'd skip the pressure regulator. Pressure on the downstream side of the needle valve will be almost zero. I would look at some sort of strainer or filter above the needle valve or you risk it gunking up on a regular basis. There's always a bit of sand & sediment in water. The only other issue you might have is variable water pressure. I think that might make it hard to dial in the exact rate you want.

Cool project. Keep us posted.

bpimm

Thats the other issue I forgot to mention in the why I use a regulator, with the well the pressure swings about 25 PSI. but for those on city water you may not have this issue, it will vary some but I don't think it will be very much. unless you are on an older system them all bets are off.

hoppycalif

Evaporation is an interesting part of the equation, one I have not considered. So, I did some rough calculations: My 29 gallon tank, in this hot weather, with 25 gallons of water in it, loses about 1 1/2 inch of water a week, which is about 10% of the total water. If my 45 gallon tank loses the same, and it should because the set up will be the same, it will lose about 4 gallons a week. The water flow into the tank to replace half of the water in one week will be about 12 ml/minute, or about 4 1/2 gallons per day. So, I will be adding water about ten times as fast as it evaporates. So, TDS shouldn't be an issue.

I'm leaning hard towards using an activated carbon filter upstream of the needle valve to eliminate some of the chloramine and most of the chlorine, possibly followed by an ammonia adsorbing filter to catch the released ammonia. Right now I'm trying to decide if that is overkill or prudence. And, I don't see a reason yet for a regulator - my water is city water, which, over a 24 hour period, should be at the same pressure every day. It makes no difference if it goes up or down 20% or more - this isn't rocket science!

Right now I am in the middle of a medical "episode" that is stopping me from actually doing much, but being a retired engineer, this type project is the most fun I have had for awhile.

JERP

I'm just going from what I read on the krib many moons ago...

http://www.thekrib.com/Chemistry/cl.html#11

Have you considered just using a holding tank/sump as a water source? Fill it up, add Amquel, and come back next week and repeat.

I usually use water changes as an excuse to clean the tank.

hoppycalif

JERP, chloramines do degrade eventually. Nothing I have read disagrees with that. The advantages of chloramines for treating water are that they remain in the water much longer than chlorine does, and don't form carcinogens with other water contaminants. I haven't seen anything yet about just how long chloramines will remain if you fill a bucket with the water, for example. Is it years, months, days, centuries? Do you have any references that provide that kind of information?

hoppycalif

Thanks, JERP! I remember reading that series of posts a couple of years ago. Isn't it amazing that the definitive answer on chloramine is still so elusive?

My goal is to divorce myself from the hassle of dragging in my water change kit, hooking it up, changing water, then getting it all back into storage, without spilling any water in the process. I have this new tank (used)I bought that has a drilled hole for an overflow, and Brian's continuous change system is just too intriguing an idea for me to forget. I was thinking of a holding tank with the incoming water going thru it, slowly of course, and dosing that tank with Prime. But, it doesn't look like that would be effective, plus it would be one more daily dosing task to do. So, I think I would be safe enough just using a carbon filter made for undersink filtering, and change it every 6 months. No one seems to have landed a fatal blow to that idea over the years.

I will plan to do a normal drain and refill change about monthly and do my major "gardening" then. In my dreams of course, I will not have algae issues requiring more closely spaced gardening.

bpimm

I think you are on the right track with the carbon inline filter, it will be interesting to see your ammonia test results.

I don't know how it will work with the EI ferts, but with the soil substrate I use if I get algae starting, I crank up the water change rate and starve it, this may be detrimental to your plants without the nutrients in the soil.

right now I have two new tanks cycling and both have small amounts of algae, I have been able to control it with the water flow rate and the algae squad in each tank.

Brian

hoppycalif

I'm back to this project again: I have my filter, my pressure regulator and my needle valve now. The filter is from Home Depot (about $30 including the filter element) and it takes standard sized filter elements - the one I purchased is a carbon one. The pressure regulator is from ebay at an absurdly low price ($2, as I remember plus $4 shipping cost). The needle valve is also from ebay, where I got 3 of them for 99 cents plus $5.01 shipping cost. (I am offering two of them for sale here today if anyone else wants to try this system. This valve will be perfect for this use.)

Tom Sharland

I use a 3 pod, sediment, chlorine/chloramine, heavy metal, filter unit manufactured by Pentek Filtration (an American company I believe). I purchased this from a UK based Discus breeder and importer. It won't alter the kH/gH/pH of the water but will remove all sediment down to 0.5 micron, breaks the NH3Cl2 bond and then removes chlorine and ammonia, finally it removes toxic heavy metals. Purchased from here. I use the DD HMA80C

When I do a rainy season on my river tank I siphon tank water out on to my garden through some 5mm id pvc pipe used on RO filters, the water is then fed directly from the mains supply, through the heavy metal/chlorine/chloramine filter and into the tank where a float valve controls the level in the tank (ie as the water siphons out, the level drops the float valve and lets fresh filtered water into the tank).

I leave this running for days at a time and the temp in the tank over the summer only drops 2 - 3 *C. But after a day the nitrates in a heavily fed, unplanted tank, are barely detectable. The fish go into full spawning mode .

Tom