Backyard Aquaponics
A place to discuss aquaponics

We are out looking for heaters to get the water temp up to what is need for the vegies seedlings to grow. Since we will be using the system year-round, I know we will need one. The question is, what exactly are the temperature requirements. I had heard that 65-70 deg is about right, but would really like everyone's opinon before I step off that ledge and buy the heater.

Lucky for you, I just did this same thing

My seedlings took off when my water temp got up in the 68F range

It will also depend on your fish, some don't like it hot and others do. I know many seeds like the temp even as high as 80 F for germination but I expect you will be better off not going above 70.

I have trouble with seedlings damping off in my system. My water temp ranges in the mid-80s. Wonder if that is the problem. Hmmmm.

Got the heaters today. Spent a little extra to get the unbreakable aluminum casings. According to the chart, I should be able to raise the water temperature at least 20 deg. Water temp right now is at 52, but they have only been in about 6 hours, and the water has been circulating, so it will take time to heat up. I had priced a single pro-titanium 1000W heater, but decided on 3 250W instead. I only need 750W, and this way, if one fails, I will still have the other two. I am putting two in the FT, and one in the sump. The one in the sump is so that when the flood cycle kicks off, I won't be pump dramatically colder water into the FT, as I suspect the fish won't like it. I plan to run the temp at 68-70 on an ongoing basis.

i think lettuce prefers lower root temps versus higher ones. dont have the figures, sorry.

We have a whole tray of lettuce waiting to be planted, so if I need to keep the water temp lower for it, that is okay. I set the heater on the lowest setting as I wanted to take the temp up slowely. Does anyone know what themp needs to be?

Beltie

From SRAC fact sheet,


Water temperature is far more important than air temperature for hydroponic plant production. The best water temperature for most
hydroponic crops is about 75 °F. However, water temperature can go as low as the mid-60s for most common garden crops and slightly lower for winter crops such as cabbage,brussel sprouts and broccoli.

Thanks for the info, I am slowely moving the temp up, so hopefully we can put these lettuce sprouts in over the next several days. I need more fish at this point. Hopefully in the morning. I am expecting to get some from the squeezing of my indoor aquarium.

Might be, but might also be water level. The stem of the plants often does not like to stay wet, esp when seedling. I had all mine damp off (two or three rounds) until I lowered water level. I had to water them that round with AP water until they sprouted as they were in dry gravel, but once they sent down roots there was no problem. I suppose one could also simply adjust autosiphon level.

Be careful that your heaters do not touch your plastic-walled tanks. I created a 3-heater array with a slice of PVC and a brick that you might like to try to replicate. Check my system thread in the last few pages. Should be a pic.

I will do that. The heaters we bought are encased, and are supposed to not have those problems. I don't like to crowd heating elements, so I have them well separated from each other, but I will look at your post. I have them on separate sides of the tank so as to spread out the heat. Thanks for the advice.