Backyard Aquaponics
A place to discuss aquaponics

after testing my Ph this morning i noticed a definate drop from 8.2 to 8.0 so added another 10mls and will test again tomorrow morning to see if we are any closer.

tested again today and levels read:

PH: 8.0
amm: 0.25
'ites': 0
'ates': 0
temp: 24C
volume: 500lts

As you can see after I added my second 10ml of Hyd acid the PH has not come down any more. I added another 10ml of acid today and will test again this arvo. Could this mean that something is buffering my PH at 8 or even raising it?
I got to the source of my high PH and my suspicions were right. I tested our tap water here in Lancefield and it is 8.0 straight out of the tap so looks like i'm up the creek to start with.
I do have 2 x 3000lt rain water tanks but they are a bit low on water at the moment due to a little mishap with the soil vegie garden. Lets just say the tanks were full 2 weeks ago and now they are below the 1/3 mark but i do have some massive carrots!
I may be better off using the tank water instead of the high PH tap water.
I have also thought about hooking up one of my down pipes off the shed to the grow bed and then putting an overflow in the fish tank either to the SW drain or on to the pumpkins in the soil garden.
This way when ever it does rain (which is not very often up this way) it will top up my FT but not let the water level get too high.

Re-tested this arvo and the PH has droped from this mornings tests. My PH is now at 7.6 but it will take another test tomorrow to see if it is holding.

That's about what it should be Bundy... think the last test was actually 7.8... not 8.0...

You should be getting a 0.2 movement with each 10ml... and a 0.2 movement in pH wont stress fish at all...

You could even go to 20ml... and move toward 7-7.2... but that's a much larger movement, and you'd need to wait a few days for the fish to get used to it before adding anymore...

Probably best to just keep nibbling away at it.... you might find once you get around 7.4... that the nitrification really kicks in... and you suddenly end up around pH 6.4...

Nope. Only if it drops below.

Well merry christmas to every one. I tested my water tonight and guess what, its back up to 8.0. Something must be raising my PH. If my tap water starts at 8 and i'm getting readings of 8.2 - 8.4 at times this must mean somethings if forcing my PH up. It was definately down yesterday. I tested about 3-4 hours after adding Hyd acid and it was definately down to 7.6, I tested 3 times. Any thoughts as to what could be raising my PH. could it be something in my FT or the FT itself.

How's the water?? Any signs of algae or greenish water?? Algae present in the water will swing your pH through the day... Hence it would be best to test for pH at the same time of the day as the previous... from memory at sunset, the pH is higher, at sunrise the pH is lower...

What media are you using in your growbeds??

The last 2 tests have been roughly the same time of day, around 5-6pm. The water is very clear there is a bit of muck in the bottom of the FT which gets stirred up if you move things around. there is a string of green algae hanging from my syphon outlet which dumps directly into the FT. Does Algae raise PH levels overall or just cause it to swing. I could run another test this morning and see if its up or down on yesterday's test as i have stopped adding the Hyd Acid.
Check back in this thread for the photos of my system it shows clearly the FT and the things that are in it, and also the grow bed which i'm using clay pebbles as my medium, which from reading this and other websites is supposedly the best for AP. Is this right?

Just retested and its on the high side of 8. Added 20ml of Hyd Acid to see if I can shock the system down to 7.4 and maybe get that Nitrification happening that Rup was talking about. If I get that to happen will it be under control or should i add a bag of shell grit to buffer from a free fall.

Shellgrit wont do anything for you.. at the moment...

Hey Rup, been looking at your website and feed for silver perch. I'm currently using gold fish feed for my perch. Would I do any better with your high protein feed. and if so what size?

BB, you'll get massive difference by using proper commercial feed. Goldfish food is designed to not foul aquarium water, and as such has very little in the way of nutrients.

For tiny silvers go a 40% protein food, as they get bigger you can cut it back to 30% to reduce fat content of the fish.

I tend to buy 4mm pellets for all my fish, I just blend it up for the littlies.

Bundy,

I can really only can say what happened in my system which is very similar to yours.
My system was started mid september 2009, 600 - 650l FT, 300l GB, on a bell siphon @ about 2 -3 p/h, the only big difference is my media, Blue metal rock. (12-15mm screenings)
My ph stayed up (7.8 ) and i never had a nitrate reading. Then i noticed my plants suffering.
I've since read that elevated nitrates will produce nitric acid and will cause the PH in the AP system to drop.
so I increased my feed 3 weeks ago to produce a nitrate reading.
After 1 week my PH dropped like a sack of potatoes.
I've noted that in my system if I keep that nitrates 40 or higher i can expect a PH reading less then 6.4
But if i can keep them between 20 -40 my PH rises to 6.6 - 6.8
I also noticed a bit of green slime in my FT or outlet of my pump seem to indicate that there is nitrate in my system. (see a recent photo of my FT below) Can't see any trace of that in your system.

My personal opinion is to wait till or try and get a nitrate reading. You don't seem to have too much in your grow bed to take the nitrates away, and your plants don't seem to be absorbing, so it shouldn't be to hard.
Can you increase the feed?? or are the SP leaving a lot behind?

Regards

Matt

Hi BNDYBEAR,

as I said you have no nitrate reading, you don't have many fish, your not producing much ammonia, I would add the nitrate in the form of a cup of seasol.

Even with the high PH, the amount of water in your system could not lock up all the nutrients in the seasol,
your plants will get some food if it's not too late for them.

I thought to cycle you need ammonia and some nitrates to kick the process along a bit. I would leave the PH for now and get the system moving and grow some bacteria.

I started my system with a high PH from quartz/river pebbles as media. I loaded my system with nitrates using a composted chook poo teabag to feed the plants. The nitrates levels shot up, water turned greenish, got ammonia readings and then the system was cycled. PH dropped back to around 7.4 from 7.8 and has not changed since.

You can see my system readings and plant growth during cycling here;
viewtopic.php?f=18&t=3665&st=0&sk=t&sd=a&start=75

Hope this helps, and God bless froggo.