Backyard Aquaponics
A place to discuss aquaponics

How high should the water in the grow tanks be in a flood and drain system?

about an inch below the gravel surface or there abouts

How high in the grow bed do you mean. The aim is to have it below the top of the gravel, but not too far below otherwise you will have trouble with seedlings and gettign seeds to sprout. 1cm below is okay - reduces evaporation but achieves the other aim.

thanks !! the water is in! the fish will be in soon. I'm planting seedlings too. Pics this afternoon.

while the plants are recovering and you're waiting for seeds to sprout, you can hand water them with a watering can to help them along.
I've been doing that with the seeds here. There are a few that have not sprouted but most are good.

Got my ruler out 1cm might be a bit little in hindsight - try for 2 - the gravel will get damp a bit higher up anyway.

Are you using timers or autosiphons forest?

or add a further 0.54 cm and go with my 1 inch

I am dubious about what you think an inch is Steve

hehehehehehe, why, what do you use as a measuring stick?

vb, I was under the impression that 2.54cm represented an inch also - looks like Steve (through patience, persistence and perseverence) has finally got one back on ya (those "P's" just keep croppin' up)

we are using a timer, VB.

Ell - I think you misunderstand. It was meant to be a rather crude joke.

Forest - why, you have the perfect setup for using a continuously running pump and autosiphons . Go the bell siphon - I am such a fan I just have to tell everybody

Ok VB... here's a supplementary question....

I'm thinking of a continuously running pump to a couple of header tanks that drain to multiple grow beds (like EB's bucket manifold)....

Would it be better to fill the header tanks quickly by using ...say 25mm... pipe and then switching the pump off with a timer....

or fill the headers more slowly using 19mm poly tubing and just run continuously... will be auto-siphon drained...

12V pump rated @ continuous.....

What's better for the pump in terms of pump life??

A pump that is one that is genuinely built for continuous 24/7 operation will last longer if it is no switched on and off all the time. As we have discussed previously - pumps sometimes include the word continuous in their literature but it does no always mean it is for continuous runnin - 24/7.

As for the main question - I'm not that familiar with EB's barrel system. Could never quite get my head around it all without seeing it in person. I thought the header tank was to help get even flow to each barrel - is that correct.

The problem with using a header tank in the way you described is that if fillign quickly then turning off the header tank needs to hold nearly as much water as the grow-beds. If you were to run autosiphons on your beds - then I think you could do away with the header tank altogether. Just run a line to each bed - adjust the flow to the bed to somethign within the start/stop margins of the autosiphon and you have it. Doing this you would run the pump continuously.

I know - I was trying with subtlety to clean it up