2 teaspoons per gallon like you were using is what I would use.
Here is some DIY stuff on cooling your bucket temps if you don't got money for a chiller.
Note: submersible pumps add heat. Use an external/inline pump to minimize heat transfer. High quality digital thermometers are recommended.
* Add cold water when topping up.
Note: abrupt changes in temperature may shock roots.
* Frozen pop bottles/milk jugs.
Fill to ¾. Keep extras in the freezer to replace thawed bottles with new frozen ones, replace as necessary. Note: "Freezy packs" tend to crack and leak.
* Increase size of reservoir
Larger volumes are slower to warm up, pH/ppm is more stable and tank changes are less frequent.
* Put reservoir/bubbling buckets onto floor, or set on concrete blocks to conduct heat away from the water.
* Insulate
Paint all exposed system surfaces white or use reflective material (such as mylar or reflectix). Wrap insulation around tank. Use a camping cooler for a reservoir (pre-insulated and comes with a drain!).
* Swamp cooler
Blow a fan directly across the surface of reservoir for excellent evaporative cooling. This method works well (expect a 10F drop in res. temp), but humidity and tds will increase, and more frequent topping up will be required.
430 scrog "…add a computer fan to a duct blowing into your tank (cut air exit holes). You can run it on a timer (1 hr on, 1 hr off). I run a float valve to keep it topped up."
Make sure lid and reservoir can be easily removed.
* Blow air through the root zone
Divert small amounts of cool intake air directly into the root zone.
* Remote reservoir
In-room reservoirs will quickly heat up to room temp. Put the reservoir (and ballasts) outside of the grow room to minimize tank heating.
* Airstone / Power head / Venturi air supply should be drawn from a cool source (ie. Cool outside air).
* Peltier coil (Thermoelectric chillers).
(Bayou grower) "I use an Ice Probe ($125) and it works well. It uses 50 watts and pulls the temp down 4 degrees under ambient. Cools 10 gal or less." (see coolworksinc.com for more models)
* Reservoir chillers
These are electric A/C units made specifically for cooling water. (Search for "Aquarium chillers")
(smokin fl) "…a heavy box with fan and compressor coils, with a 5 foot refrigeration line with a titanium coil at the end. All you do is plug it in, set the controller and put the coil in the res. Circulate nutes for the best cooling. Get a bigger model than you need."
* Cooling coil
homemade stainless cooling coil A coil of stainless steel is put into the reservoir, cold tap water is trickled through the coil and the overflow runs down the drain. A circulation pump in thte rez makes the cooling more efficient. Adjust tap flow as necessary (Water use can reasonable). No power, unlimited cooling, quiet.
Making your own cooling coil:
Scrap yards and appliance repair shops are full of A/C and fridge coils: 4-20 loops (more surface area is better), with male garden hose connectors welded to each end (Don't use copper or nickel coils). Available in Hydro stores (around $100 cdn).
Note: Cooling coils may not be useful for those on metered water.
DIY heat exchangers: try hot tub suppliers, home brew stores.
Here is some DIY stuff on cooling your bucket temps if you don't got money for a chiller.
Note: submersible pumps add heat. Use an external/inline pump to minimize heat transfer. High quality digital thermometers are recommended.
* Add cold water when topping up.
Note: abrupt changes in temperature may shock roots.
* Frozen pop bottles/milk jugs.
Fill to ¾. Keep extras in the freezer to replace thawed bottles with new frozen ones, replace as necessary. Note: "Freezy packs" tend to crack and leak.
* Increase size of reservoir
Larger volumes are slower to warm up, pH/ppm is more stable and tank changes are less frequent.
* Put reservoir/bubbling buckets onto floor, or set on concrete blocks to conduct heat away from the water.
* Insulate
Paint all exposed system surfaces white or use reflective material (such as mylar or reflectix). Wrap insulation around tank. Use a camping cooler for a reservoir (pre-insulated and comes with a drain!).
* Swamp cooler
Blow a fan directly across the surface of reservoir for excellent evaporative cooling. This method works well (expect a 10F drop in res. temp), but humidity and tds will increase, and more frequent topping up will be required.
430 scrog "…add a computer fan to a duct blowing into your tank (cut air exit holes). You can run it on a timer (1 hr on, 1 hr off). I run a float valve to keep it topped up."
Make sure lid and reservoir can be easily removed.
* Blow air through the root zone
Divert small amounts of cool intake air directly into the root zone.
* Remote reservoir
In-room reservoirs will quickly heat up to room temp. Put the reservoir (and ballasts) outside of the grow room to minimize tank heating.
* Airstone / Power head / Venturi air supply should be drawn from a cool source (ie. Cool outside air).
* Peltier coil (Thermoelectric chillers).
(Bayou grower) "I use an Ice Probe ($125) and it works well. It uses 50 watts and pulls the temp down 4 degrees under ambient. Cools 10 gal or less." (see coolworksinc.com for more models)
* Reservoir chillers
These are electric A/C units made specifically for cooling water. (Search for "Aquarium chillers")
(smokin fl) "…a heavy box with fan and compressor coils, with a 5 foot refrigeration line with a titanium coil at the end. All you do is plug it in, set the controller and put the coil in the res. Circulate nutes for the best cooling. Get a bigger model than you need."
* Cooling coil
homemade stainless cooling coil A coil of stainless steel is put into the reservoir, cold tap water is trickled through the coil and the overflow runs down the drain. A circulation pump in thte rez makes the cooling more efficient. Adjust tap flow as necessary (Water use can reasonable). No power, unlimited cooling, quiet.
Making your own cooling coil:
Scrap yards and appliance repair shops are full of A/C and fridge coils: 4-20 loops (more surface area is better), with male garden hose connectors welded to each end (Don't use copper or nickel coils). Available in Hydro stores (around $100 cdn).
Note: Cooling coils may not be useful for those on metered water.
DIY heat exchangers: try hot tub suppliers, home brew stores.