Backyard Aquaponics
A place to discuss aquaponics

hence the idea of raising your pump slightly...................................

it will burn out at 3 inches of water, that'll be enough for my 5 little goldies for a day or so.
once the water reaches top level of the pump it'll break suction and burn out in about 10 seconds flat.
what i meant before is i'll need to put more precautions in for my larger setup since they will be higher stocking and just burning the pump out like that won't save them if it happens while i'm out at work.

you'll be surprised how long a pump will last "dry" mine did for hours.

As long as it is in some water there will be partial cooling, and what will happen if there is a half decent head is that the impeller will take in air, the water head in the pipe will fall back flooding the impeller which will pump a certain head again, and cycle repeats amking much slushing noise. the particular pump in question is still serving my system now.

it's been almost a month since i first put fish in the system, and for those who questioned it here is my first water test - test kit arrived 15 minutes ago.
for my money i'm guessing:
ph 8
ammonia < 0.10
nitrite < 0.10
nirate 7 - 8

the only thing on there that looks a little out of whack is the PH, but everything is doing really well so i'm not inclined to change it.

I added 20L of water about 24 hours ago but that shouldn't have changed things much, so i think these figures are a pretty accurate representation of thing. fish are well, plants are growing.

much nirate do the plants really use? i've got the number of 10ppm in my head as an ideal level? can i tune things and get better growth from here or are these figures as good as it gets?

Run the High Range pH test, too. Or did you, but you didn't show the card? The test you show is the regular card, and only goes up to 7.4, I think.

Your ammonia and nitrite look good, but yes, you could use a little more nitrate. Feed more or get a few more fish. I'm happy if my nitrate is anywhere between 5 and 20.

i'll try feeding them more and see how i go with nirtates. i didn't run the high range test. if it's high, should i bring the ph down, and if so how do i do it? i know i need to step down gradual, can i just use disovled iron sulpate?

Lost ya there Timmy.... what do you want to use the iron sulphate for?

He's contemplating bringing the pH down with iron sulfate, Rupe.

Over time, your pH will naturally drift down, but if it is over 8, you might consider putting a little lemon juice in the system. I don't know what the fish would think of iron sulphate.

Hadn't heard of using iron sulphate for pH buffering....

Where did you here/find info on that Timmy?

And where can it be obtained.... obviously if it's soluble then the "sulphate" ions combine with water to produce an acidic effect (weak sulphuric acid) and the iron could be perhaps and alternative to the use of chelated iron.... if it's a soluble salt....

Or does the iron precipitate out as a powder Timmy... any idea?

Humm... just checked the MSDS....

http://www.gardenhealth.com/msds/straights/iron.pdf

Seems it is listed as having possible adverse affects on aquatic organisms

(page 6- data relevant to rainbow trout)...

and more particularly is said to lead to oxygen depletion in large concentrations.

Eating it can apparantly cause death

This may not be theplace for it but can someone clarify my understanding of acidity etc.
I had the feeling that the hydrogen ions (H+) increased the acidity during dissasociation form the other half of the molecule e.g Cl.

Thus iron sulphate will dissociate to fe and SO4 meaning no H+ ions thus limited effect on pH.

Any way if you need to bring a large volume of water down in pH try your pool shop they use HCl to clean the chlorinating cells. It is pretty strong but I don't think it is that expensive.

isnt' ferous sulphate an iron supplement? i cant see what use it would have as a PH modifier.

it is only useful as a iron supplement at below 7 pH i think. but may be of use if it can be bio-converted.

iron sulphate is a common ph adjuster for dirt gardens. i have a big bag of it here that's why i asked.
i will use the lemon juice if that's what is recommended i do - how many grams per litre do i use?

I'm not sure what fish would think of HCl, either. I suspect they wouldn't appreciate Chlorine that probably is released from the use of that, Nick.

Timmy, I can't tell you how much lemon juice to use--never had pH that ran too high. Start low and work your way up.

i did the high range ph test today - my ph is definately an 8.
I might just hold off trying to adjust it for the moment and see how it settles.
i've started feeding every day now, i'll retest next week and see how my water is