Water Topic

[Giorgio]

We have a plant topic and fish topic I think we need a water topic as water is the most important part of what we do.
I'm collecting rain water to use in AP and gardening but I read is not safe to use especially from asphalt shingles and other treated roofing systems. Is anyone here using rainwater? and how to filter it simply and cheaply?
Mahalo

[TCLynx]

Sahib Punjabi said:

I came across an interesting filtration method today, one using "Coir". What a wonderful idea especially if you subsequently use some of the coir as part of your medium for seed starting. Does anyone else use this method of filtration? http://www.kitsapsun.com/news/2010/sep/17/backyard-aquaponics-shows...

I'm not immediately finding a description of the filtration you mention. Can you point us to the exact reference or perhaps describe it for us?

Oh, sorry, I found it now, it's in the video. They don't really explain much about the filter. Just show the water being run through a bin with coconut fiber as a filter. I wonder how long they have been running it and how often they have to change out the fiber when it gets too clogged with fish waste or starts to rot down. I also wonder if they experience renewed ammonia/nitrite spikes when they do change out the fiber as I'm sure it contains a huge portion of the Bio-filter bacteria since it gets first crack at the ammonia.

I also notice that he says carrots rot. Well yea, if they are constantly submerged but I've grown lovely carrots in flood and drain gravel beds.

[Sheryl Gambardella]

Hello all! I am new to AP and having problems with my new system. I know it is the water- I have learned so much from reading on this site. But I wish for a place to put down the specifics and to get some feedback!
I started a 160 gallon stock tank with 4 Zip grow towers 10/9/10. I introduced 10 gal water from my outdoor goldfish tank and ran the system for 11 days then added lettuce type plants and seaweed/fish fertilizer for another 14 days and then added the 30 small goldfish. Locally purchased testing kits were poor quality so the info from this time is sketchy but certainly the water pH was high and best guess now that it was 9. The pH Down product from the aquarium store started killing the plants so I changed out 50% of the water with rainwater (pH 7.2) twice and now have these readings: Ph 8.4, Ammonia 0, nitrite 0, nitrate 10 to 20, alkalinity 300, hardness 0. Water temp now ranges from 60 to 68 degrees(it was steady at 68 to 70 until 3 weeks ago), Air temp from 45 to 95 (its in a sunroom). The system has already had a small ammonia and nitrite spike and we have a little algae growing. The fish are doing OK but the plants- which were doing fair at first- are now dead and dying. And now no more rain water left.
I read on this site that General Hydroponics pH Down is safe for fish and plants so that is what I am planning to use to slowly bring the pH down. My question I guess is.... has any cycling happened at all? and what I might I expect when I bring the pH down?

[Sheryl Gambardella]

So reassuring to have that information. Funny enough- when I needed emergency plant replacements- mints and basil, herbs and garlic were all that was available and so thats what is struggling its best for me now. I have swiss chard seedlings coming along now. I will nurse this through the pH adjustment and see what happens. And let you know. Thanks from another arid area :)

Kobus Jooste said:

If you have any nitrates without adding it with fertilizer, then some cycling would have happened - I think the very high pH would not have been as bad for the bacteria as very low pH. Funny thing is most people try to add lettuce as a first plant to AP and they can be quite full of nonsense in a new system. I would try to get the pH down to at least 7.5 over about a 48 hour period (not to bomb the fish or bacteria out with sudden swings) and then try again with a mix of leaf crops such as lettuce, mint, basil, parsley atc to see if it was maybe the plant species you chose that were unhappy. Goldfish are quite tough and if you do not want to loose more water (I know that feeling), you should be able to nurse the system to correct pH without too much problems. Most basic kits do not pick up ammonia and nitrate levels well, but if you have alage, you have nutrients. You could start treating a container of tap water with a bubbler on the side just in case you do need to make a change, but I pulled a AP system with Ammonia levels of 7.5 mg/L and Nitrates of around 50 mg/L back to normal without changing the water and did not loose a fish - you will have to keep a close eye on it though for signs of stress with the fish.

Sheryl Gambardella said:

Hello all! I am new to AP and having problems with my new system. I know it is the water- I have learned so much from reading on this site. But I wish for a place to put down the specifics and to get some feedback!
I started a 160 gallon stock tank with 4 Zip grow towers 10/9/10. I introduced 10 gal water from my outdoor goldfish tank and ran the system for 11 days then added lettuce type plants and seaweed/fish fertilizer for another 14 days and then added the 30 small goldfish. Locally purchased testing kits were poor quality so the info from this time is sketchy but certainly the water pH was high and best guess now that it was 9. The pH Down product from the aquarium store started killing the plants so I changed out 50% of the water with rainwater (pH 7.2) twice and now have these readings: Ph 8.4, Ammonia 0, nitrite 0, nitrate 10 to 20, alkalinity 300, hardness 0. Water temp now ranges from 60 to 68 degrees(it was steady at 68 to 70 until 3 weeks ago), Air temp from 45 to 95 (its in a sunroom). The system has already had a small ammonia and nitrite spike and we have a little algae growing. The fish are doing OK but the plants- which were doing fair at first- are now dead and dying. And now no more rain water left.
I read on this site that General Hydroponics pH Down is safe for fish and plants so that is what I am planning to use to slowly bring the pH down. My question I guess is.... has any cycling happened at all? and what I might I expect when I bring the pH down?

[TCLynx]

Hang in there, slow and steady but I expect things will get better.

[David Acklin]

I have a question about what to use for the storage of water I found these tarps online http://www.amazon.com/Heavy-Duty-Vinyl-Tarp-Billboards/dp/B002EKZMT... they claim to be useful for ponds and stuff but I am building a deepwater culture system and wanting to use rammed earth for the fish hold and grow tanks does anyone know if these vinyl tarps are safe to use as a liner ive been looking at the HDPE liners and http://www.pondarmor.com/ which claims to be non toxic but the prices for the sizes I need are outrageous.

 

[TCLynx]

I'm not a big fan of flexible pvc or Vinyl.  There are some Vinyl liners that claim food grade but I doubt the billboard tarps can claim that.  Even the ones that are food grade, the plasticizers they use to keep them flexible are questionable in my book.

That said, I am using some of the billboard liner as the bottom of some regular soil garden wicking beds.  See, I'm not going to go out and get any more of them but........ If I have something on hand that could be useful in the garden, I'm likely to use it instead of sending it to the landfill in order to go buy something else.

Now if you don't have the billboard liner on hand, I'll give you this warning.  It is used, there is no guarantee the one you get won't have holes or abrasions or pinhole leaks and there is no guarantee that the materials used are really safe long term so I would probably advise getting a high quality liner.  The Durascrim liner is good and food grade.  Or for more ornamental use and even for personal backyard  garden use, the EPDM firestone pondguard liner is good stuff and can stand up to abuse from rocks.  The durascrim is not terribly flexible so I would restrict it's use to rectangular tanks and troughs.  The EPDM is flexible and far better for fitting into a more complex shape for ornamental ponds.

[David Acklin]

Thanks for the info TCLynx that helped a ton.

TCLynx said:

I'm not a big fan of flexible pvc or Vinyl.  There are some Vinyl liners that claim food grade but I doubt the billboard tarps can claim that.  Even the ones that are food grade, the plasticizers they use to keep them flexible are questionable in my book.

That said, I am using some of the billboard liner as the bottom of some regular soil garden wicking beds.  See, I'm not going to go out and get any more of them but........ If I have something on hand that could be useful in the garden, I'm likely to use it instead of sending it to the landfill in order to go buy something else.

Now if you don't have the billboard liner on hand, I'll give you this warning.  It is used, there is no guarantee the one you get won't have holes or abrasions or pinhole leaks and there is no guarantee that the materials used are really safe long term so I would probably advise getting a high quality liner.  The Durascrim liner is good and food grade.  Or for more ornamental use and even for personal backyard  garden use, the EPDM firestone pondguard liner is good stuff and can stand up to abuse from rocks.  The durascrim is not terribly flexible so I would restrict it's use to rectangular tanks and troughs.  The EPDM is flexible and far better for fitting into a more complex shape for ornamental ponds.