What would you do?

[wh33t]

No, the nitrates are fine. Flood and drain grow beds rarely have problems with oxygen, but you mentioned root rot... The correct way to calculate the required gallons and relevant surface areas is tedious and unless you already have an understanding of it, it's really too much to post here. Stick with the general "pounds per gallons" and "square feet grow bed per pound" rules of thumb provided by Oliver. The rest will be trial and error for most folks, which is part of the fun; so, enjoy it!

Anaerobic bacteria would cause denitrification, which causes an increase to your pH: 6NO3- + 5CH3OH => 3N2 + 5CO2 + 7H2O + 6OH

Anyway, the shell grit in a removable bag of some sort a great suggestion to adjust the pH problem. Not only will it bring it up, but it will allow the solution (water) to buffer itself.

What do you mean the Nitrates are fine? I was asking if the nitrates are a good way of measuring the health of the system. If you have lots of nitrates in theory you would lots of fish waste right?

Currently I must not be experiencing dentrification because my PH keeps lowering steadily.

Also, I have shell grit in my system. As well as organic free range egg shells. They sit in my particle filter in the gravel from my drive way.

[Larry Dietz]

What kind of gravel do you have in your driveway?

I know around here, gravel driveways tend to be crushed granite and limestone. Either of these I would expect to steadily raise your PH.

I dont know of any type of stone that will push PH down, off the top of my head, but it might be something to look at.
Sorry if I am way off base here, but when I saw "gravel from my driveway" it just stood out.

Also, did you make sure to clean that gravel fully? Stones in a driveway tend to become contaminated with all kinds of things that are bad for both plants and fish.

-Larry

[keith_r]

if your ph was dropping before adding the buffers, i'd think that the media was ok..
the buffers should do the trick, but you may need to add a little more..
high nitrates are usually only problems for fish over 3 or 4 HUNDRED... but a balanced system should have them lower..get more plants in to use them up

[wh33t]

What kind of gravel do you have in your driveway?

I know around here, gravel driveways tend to be crushed granite and limestone. Either of these I would expect to steadily raise your PH.

I dont know of any type of stone that will push PH down, off the top of my head, but it might be something to look at.
Sorry if I am way off base here, but when I saw "gravel from my driveway" it just stood out.

Also, did you make sure to clean that gravel fully? Stones in a driveway tend to become contaminated with all kinds of things that are bad for both plants and fish.

-Larry

The gravel is crushed up 3/4" stuff. I'm not sure what kind of rock it is exactly but it looks like the very typical kind I've seen in many other peoples Aqua systems including Murray Hallams. I did clean it for quite sometime, but now that I think about it I'm not sure if I did clean it all that well. At any rate, the problem in the system is root rot and I'm not sure contaminated gravel would increase such a thing. But it might be something I have to look into after.

if your ph was dropping before adding the buffers, i'd think that the media was ok..
the buffers should do the trick, but you may need to add a little more..
high nitrates are usually only problems for fish over 3 or 4 HUNDRED... but a balanced system should have them lower..get more plants in to use them up

I can't put more plants in, they die from root rot and slimes and such on the roots. So far I have taken away a bunch of fish though and now I'm trying to be patient and see if the system will come back into balance.

[urbanfarmer]

I was asking if the nitrates are a good way of measuring the health of the system. If you have lots of nitrates in theory you would lots of fish waste right?

No.

[keith_r]

you're way overstocked..you have to much waste going into the growbed if you're experiencing root rot.. as uf said, try to get an air stone or two in trouble spots.. add composting worms to assist in breakdown of solids in the growbed/gravel - they'll be fine submerged as long as you have good DO
a good starting point for hobbyist/backyard aquaponics systems stocking density is 25 lbs (grown out size) for every 100 gallons of filtration..
so 25 fish you plan to grow to 1lb for every 100gal of gb

[wh33t]

Yes, I had a feeling I was over stocked for some time. Now I have about 1/10th as many fish and I painstakingly last night cleaned my entire flower bed out. I put all of the heavy solids into the compost We'll see what the plants in there do now.

[keith_r]

some worms will help in the growbed, red wigglers can usually be found at bait shops

[wh33t]

some worms will help in the growbed, red wigglers can usually be found at bait shops

I don't think they will as my grow bed doesn't have any medium in it. Just water. I do have some big fat dew worms in my heavy particle filter though. If they are making a difference I haven't noticed it at all yet.

[urbanfarmer]

some worms will help in the growbed, red wigglers can usually be found at bait shops

Any detritivores can help if they are in large enough quantity. I forgot the name... darn, I will post if I remember to, but they were small shrimp like ones that actually swim around and typically latch on to the roots and eat up all the decaying organic matter. They have had good results, and we have it in our system in Nicaragua with some of the plants that are only floating in water. The Friendly's also use these critters... darn I can't remember the name...