Backyard Aquaponics
A place to discuss aquaponics

algae can cause daily pH swings, can you test the pH around dawn and again late in the afternoon. That may tell you if your pH is crazy from the water or crazy from the algae.

Well just tested it now and it is still high. 9.5 or so heading to 10 aargh! On both systems. The watercress has died off. Does that like acid conditions?

Is there no slow dissolve acid thing I can use. Hardwood planks or something?

Can I put the koi with the tilapia?

The rain water tanks pH is the best at between 7.5 and 8. Problem is there is not a whole lot of it.

Brian sorry to hear the troubles you are going through at the moment

Out of interest, could it be possible your wicking beds are pushing the PH up? Its hard to tell when you read through a thread but seems your fish started dying after you introduced the wicking beds, maybe test some soil.

Hi Charlie. Nah. The pH has been like that from the start. I have just accepted that some plants are just not going to grow. But it is slowing things down considerably. Besides the wicking beds are on the outdoor system and the fish are dying on the greenhouse system.

The uvi folks have an additives tank. I think I need something like that. Or just a small measure of acid daily. To fight it.

Hardwood planks or logs???

I know some people have used driftwood or peat filters or pine straw to adjust pH.
If you can put top up water in a separate tank and adjust the pH with acid before you use it to top up the system, that is often the better way to go.
Make sure algae and anaerobic pockets are not the cause of you pH issues.

Thanks Tcl. Could be anaerobic zones or algae but pH is high early in the morning so mabe not the algae. There could be anaerobic zones in the growbeds. I must check the timing and make sure they are draining out properly.

Can I just use small pine firewood split logs in a sack in the sump? Whats pine straw? Pine shavings I could create by planing some pine planks.

If I use peat in the wicking beds instead of compost. Now that would be like killing two birds with one stone. But the peat could be expensive....

lost another koi and another one is dying The dead one had string algae in its mouth lots of it. is it possible they choke on the damn stuff?

Tilapia seem ok, no more deaths and the one eyed one seems to have come right. but not very hungry considering the 30 degree water temps.... They should be ravenous...but they are not.

have a nice pile of compost sieved for the wicking beds now. Thanks to the energetic Malawian John. So they are nearly ready. tomorrow I will check out the peat option. If I can get the peat then the compost can go in the stand alone wicking beds I am working on.

Will also need some fresh test kits or at least some strips...

I have also constructed a wheeliebin throughflow wormbin. Pics coming soon soon

Just a thought... can one not put a system on an acid drip. Literally a barrel with diluted acid and a hospital drip....

Pine might not be the best wood to use. I think hardwood driftwood is preferred.
As to pine straw, I've never tried using it but Travis Hughey has I think. Pine straw is the long pine needles we get from some kinds of pines around here.

To know if using acid is appropriate, we need to know why your pH has gone so high. If something in the system is causing the pH to go up (like if you have limestone or shells as media) then adding acid won't fix the problem until all the limestone or shells have dissolved away. This will cause huge amounts of calcium to be liberated into the system and probably block potassium uptake by the plants and so is not a great option. Concrete or mortar could have a similar effect.

If it is just that your top up water is like liquid limestone, it would be better to adjust that top up water in a separate tank and letting the pH stabilize before adding it to the system. This is much safer to your system since it will allow you to bring the pH in the system down more slowly than just adding acid to the system.

Brian, Pine straw is something like this:http://mayang.com/textures/Plants/images/Dried%20Dead%20Plants/dried_pine_needles_9250031.JPG
I have tons of pine needles in my system, though, and the pH was always pushing 8+. Limestone wins in the end!

I just would have thought pine straw would have had a growth inhibitor in it. Or is that only the eucalyptus?
Was it not pine needles that screwed up EB's commercial trial? or was that eucalyptus leaves? will need to check ...

Anyway... another koi died and another one is looking poorly. And another tilapia went belly up. Grrr

My wife tells me my system is too acid. Too much coffee etc etc, So I was thinking I should just sit by the ap system all day long drinking the water and peeing it back into the sump. Then we could balance each other out

I think it was Gum leaves that gave EB a problem.
Have you had any luck figuring out why your pH has gotten so high?

Hi Tcl... no, still clueless. could using a top up water with a high pH have a cumulative effect on the pH of the system? If I keep adding high pH water say with an 8.5 could I eventually have a pH of 9.5 or 10 as the alkalinity builds up in the system?

Hi Brian, sorry to hear about the pH problems.

I haven't been all the way back through your thread so I don't remember exactly how you built your tank and growbeds or if they are lined. Portland cement used in concrete contains lime, it seems likely based on what I've read, that if the beds aren't lined, the concrete is probably leaching causing the pH to climb. Why this hasn't happened earlier , maybe you were adding more water that had a lower pH or the rocks were acting as a buffer, so it wasn't an issue.

Concrete construction is a gray area for me and someone with more experience will probably set me straight but that's my best guess at this point and I hope I'm wrong. Lining the beds would probably solve the problem.

High pH tap water can have a cumulative effect of sorts but it shouldn't cause the pH to climb that high.
Now keep in mind if you test the pH of your tap water right out of the tank or pipes, you may be seeing a false low reading from dissolved carbon dioxide trapped in the water acting as a weak acid. (like my well water will measure a pH of 7 right out of the pipes but if I let it bubble or circulate overnight it is actually like 8.2+ depending on season.)
So if your water is measuring a pH of 8.5 right out of the pipes, then the real pH might be higher.
However, the more normal issue is that you just have so much calcium carbonate in your water that you can never bring the pH down using acid until you use up all the calcium carbonate. If there is cement or concrete in contact with the water, that could well be the source of the lime or calcium carbonate messing with your water pH. If there is any media or rock or concrete or mortar in contact with the water that could be the source of the high pH buffering and adding acid will not help till all the buffer is dissolved away.

You can test media like gravel for calcium carbonate by putting a hand full of rinsed gravel in a glass of vinegar, if it fizzes alot, it probably has too much calcium carbonate.

Thanks Tcl. I'll check on the well water pH after bubbling it for a day or so. I'll do the vinegar check on the stone too. It could well be the cement contacting the water through the sealer. But the thing is the greenhouse system is all plastic and suffering the same high pH issues. Hmm I guess I could at this point do a complete water change on the big system as I don't have fish. Is it possible that sand and silt from the area that has blown into the system is causing the high pH. Guess I should do the vinegar check on the sand too.

There is quite a bit in the sump from when there was no cover. The wooden slats also have gaps so sand can get in. Could be an issue? Perhaps I should take one growbed offline at a time and re-seal them and wash the media again. I have noticed some of the beds have gotten a bit muddy particularly around the edges. But only in places.