Backyard Aquaponics
A place to discuss aquaponics

Has anyone tried growing watermelon or cantaloupe aquaponically? If not, do you think it would work very well?

I was going to try them and let them grow around the base of the grow bed. I am looking forward to some nice ones around Christmas if they work.

I was planning on tryinging to grow them one or two to a blue barrel, and trail them outside the greenhouse in case they suffer from any mildew in the damp environment.

Well, they are thirsty sort of plants, and there won't be a shortage of water

Will the plants absorb enough water to the point that more water will have to be added to the system?

Trox, I think thats going to happen regarless of what plant you have!

Well I'm really new to this. I haven't even built my system yet so there are a lot of things I don't know yet. I don't have any books on aquaponics. I'm trying to learn everything from the forum and other websites so some of my questions may sound a little silly.

Good on ya Trox.

If you dont ask you dont find out.

I think remembering back to high school that part of the photosynthesis process requires a thing called transpiration. There CO2 is exchanged with O2 and water is lost. Also if we grow monster size fruit then there will be lots of water in them.

I know with Hydroponics you use a bit of water from the plants taking it up so it will be the same with Aquaponics.

Thanks for the explanation BigRed.


So over the course of a growing period, from beginning until harvest how much water would have to be replaced for something such as lettuce versus a cantaloupe or watermelon? If there isn't a defenite answer just a relative guess will work. Thanks.

It will depend on temp and humidity so I dont think there is a way to tell for sure. I know with my hydroponics I just topped it up to a line I had on my tank each week. It usually dropped a couple of inches in a 60 ltr tank and I had about 30 lettuces.

I just googled the water content in a couple of diff things, because this post made me really curious

Water content in lettuce is 94.9%
in watermellon 92%
in cucumber 96%
in tomato 93%

Theres not a huge difference in water content of these fruit and vegetables

So water needing to be replaced for a lettuce versus watermellon, i would say you would need to replace more for the watermellon as it would be bigger and heavier (not sure the average weight of lettuces nor watermellon, so if you find these you may get a better approximation.

But then theres photosynthesis and as Big red said, water is lost through the leaves, and clearly lettuce is alot more leafy than watermellon plants...so in the end lettuce could use more water.......

someone might have a more definite answer, i seem to be just arguing in my head at the moment.....

but if i was to guess which one would use more water, i would say lettuce, as its surface area for water loss would be so much greater that that of a watermellon, and i remember reading somewhere (figures may not be exact) but an average tree transpires over a ton of water a day, as oppose to say a cactus who looses none

well it will be interesting to see what other people think about this

Interesting. I think watermelon by it's design is made to trap water, however, the plant itself has much foliage cover as well where the lettuce is almost entirely harvestable.

I think watermelon would love Aquaponics.

Trox, hope you didn't take my post the wrong way. Would have like to give big reds explaination, but i was dead tired at the time

Don't stress too much about the ifs and buts, just do it I tend to be like that too, and it was only after i realised i was going to be the only one without a working system did i get stuck into it. You need a balance.

IMHO do this:


A) Get a container for a fishtank that is as large as you possibly can.

B) Get another container of at least 25 gallons and fill it with gravel or hydro rocks.

C) Put some fish in and feed very minimally for the first 4 weeks, keep the temp between 20C and 25C if you can and the PH around the 7.5 mark.

D) don't even worry about plants for at least 4 weeks as there will only be ammonia and nitrites in the system and the plants will run out of nutes shortly after germinating

The above plan of attack will get your system "cycled" (read the useful info section)

Once you have a "cycled" system that is operating stable, you can try any number of variations on the theme, becasue your system has the THREE things you need for sucessful aquaponics.

1) fish

2) plants

3) nitrifying bacteria (with out this everything falls in a smelly heap )

Steve

No I didn't take your post the wrong way. Thanks for the information.

no worreis