Recirculating pump

Hey all, I got a quick question. When I have a pump recirculating water in my reservoir, do I put any plumbing on it, or do I just throw it in there with nothing and turn it on? I can give a better description if needed.

If your talking about just a small power head like an aquarium power head you simply put it in the reservoir and position it so that it maily keeps the suface water turbulent. v If your talking a oump that recurculates your water between the growing medium and the resrvoir it is jsut put in the reservoir "if" it is a submersiable pump. It is often best to use a filter on the intake. My favorite method is just use low micron bags available at better tropical fish stores or on eBay. Buy them larger enough to put the entire pump inside the bag. If the pump is used for hydro a 200 micron bag is fine. It you are using emitters or sprayers then get a 50 micron bag or even an 18 or so.

Thanks for the reply, I think I figured it out though. I'm just gonna put an ecoplus 396 gph pump in my reservoir and let it run all day.

your pump may heat your water more then you want. Mine did anyway.

I agree.. I was thinking about a repeat cycle timer on my stiring (recirculation) pump to avoid excess heat...

well it's going to be in a 100 gallon reservoir, so I don't think it should heat up too much. If anything, I'll have to get a water chiller.

With a 100 gallon reservoir you would need a lot of lighting/heat etc to raise the resrvoir temp up enough to need a chiller. (100 gallons * 8.33 pounds/gallon * 3.41 btu)= 2840 btu to raise the water temp one degree. If your running a 16 hour light cycle and your water starts of each day at say 70 degrees and you are allowing it to rise to 76 degrees that means a 6 degree rise in 18 hours. (2840 * 6 ) = 17040 btu per cycle. A 1000 watt light will put out 850 watts of heat nominally. An air cooled light would drop that 60%, so [850 - (850-0.60)] =340 watts of heat energy acceptable per hour. (340 * 3.41)=1159 btu. (17040/1159)= 14.70 hours until the reservoir temp rises above the acceptable temp maximum of 76 degrees.

However if the reservoir is not in the grow room and is installed in an area where the temp is below 76 degrees so that it is also losing heat during that 16 hours it is very easy to believe its temperature will not rise above the accepted 76 degrees use for the calculations. Under these conditions or If the reservoir is in an area where the night time temperature is below 70 degrees then a chiller should definitely not be needed.

However this is based upon only 1000 watts of lighting with the reservoir being inside the grow room taking in all thermal energy from the lights not exhausted by the colling tube. It is also assuming it is a sealed insulated grow room losing no heat through its walls ceiling where no heat is exhausted, no air conditioner is used so that the reservoir water absorbs heat but nothing else does. Basically it just means a room with a 1000 watt aircooled light will not get excessively hot nor will the resrvoir if it holds 100 gallons. Large capacity reservoirs help temper temperature immensely as water can absorb huge amounts of thermal energy without getting excessively warm. There are commercial growers who place many water containers in their grow rooms under the grow room tubes or tables just beacause of waters tempering abilities.

With a 100 gallon reservoir you would need a lot of lighting/heat etc to raise the resrvoir temp up enough to need a chiller. (100 gallons * 8.33 pounds/gallon * 3.41 btu)= 2840 btu to raise the water temp one degree.

Click to expand...

The math is a little adrift
It takes 1btu to raise 1lb of water by 1deg F, so 100gal of water would only need 833 btu to raise it by 1degF.
3.41btu is equal to 1watt.

Why put a pump in your res just to churn up water? You can do the same and much better with a robust air pump (that is not in your res) and 3 or 4 large airstones.

Oooooops, your right one btu per degree per pound not 3.41. (100 gallons * 8.33 poungd/gallon )= 833.3 btu/degree 1000 watts light will deliver approx 850 watts which must be removed as thermal energy. (850* 16)= 13600 watts The aircooling tube will remove (13600 * 0.65)= 8840 leaving (13600-8840)= 4760 watts of heat energy. (4760 * 3.41) = 16231 btu. (16231.6 / 833.3) = 19.48 That means a water temperature rise of almost 20 degrees if the reservoir is in a sealed grow room with no veltialtion, cooling and no heat loss through the walls, ceiling or floor.

Now I feel dumb!

Most aquarium and fountain pumps have a quite shorrtened life when they are cycled on and off alot. The actually last longer if just running 24 hours per day. To avoid the excess wear and tear it is easy to just put a solenoid on a T fitting just after the pie leaves the reservoir. Instead of using a timer to turn the pump on and off the pump runs constant and u you instead have the solem nioid open and close. When ever the solenoid is open the water flows back to the pump rather than to the plants.

Surface aeration increases DO in a reservoir more than using just a few airstone, unless the airstones are causing more water surface turbulence that what the pump would cause. Plus bursting air bubbles mean slats of salt creep. Large air bubbles have a small surface area so their bubbles in them selves add very little DO to the reservoir water. Airstones that put out smaller air buubles work better than those putting out large bubbles but clog quicker.

no heat and all of the oxygen that your babies need w/out adding h202

i circ water before feeding. I circulate the water 6 times a day and feed 4 times a day. I bought this underwater aquarium fan like deal. it has a propeller and is used for its purpose it only generates 13 watts. Its pretty awesome.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160495698154&ssPageName=STRK:MEWNX:IT

so thats my 2 cents. i have a pump that circs water before feeding and a underwater fan that runs 24/7