Backyard Aquaponics
A place to discuss aquaponics

I have 4 systems with extremely high nitrates. I plan to change the water and put the old water in soil gardens. When I dilute the water to lower the nitrates the ppm's go down to about 200. My question is, what's more important nitrates or ppm.

not sure on your question ?
Nitrates are measured in ppm (parts per million - which is essentially a ratio of mass of element versus mass of the volume of water).

200ppm is very high. So you can only drop it by either taking it away or using it.
At that level using it is not really an option. I would water change to get it down to below 80ppm.
As noted on other threads you get nutrient lockout and plant stress with excessive nitrates.
Within the tank the efficienciy of transfer from nitrites to nitrates can also be effected.

Before you get too carried away though may be best to check that you are measuring correctly.
Also check your top up water - high nitrates could reflect a chloramine issue.

From that I'm assuming you mean total ppm of dissolved salts in the water as tested with a digital ppm meter, and not just the ppm of the Nitrate. If that is the case, then I would suggest not testing the total dissolved salts in the system, it's irrelevant in aquaponics, tells you very little, and will see you chasing your own tail around in ever decreasing circles.

When you say you have high Nitrates, what are the levels?... 0.0ppm to 40ppm is fine. At 60ppm and above some greens, especially lettuce, can start to become bitter. At 160ppm and above you will find it difficult to establish some seedlings and flowering/fruit set can be affected on fruiting plants. Also, long term exposure to levels of 160ppm+ can have effects on the health of your fish.

If your system is constantly developing excessive Nitrates (ie: >40ppm) then you need more fast growing leafy green plants, or less fish food inputs or fish in the system. In the short term you would stop feeding, carry out regular, partial water changes (ie: 25-30%) and plant plenty of fast growing leafy greens (ie: Lettuce, Bok-choy etc). Once you have the Nitrates down to an acceptable level you would resume feeding with a good quality commercial grade fish food and add a capful of Seasol (Maxicrop) per 500L per week to help boost up the diluted trace elements and Potassium etc.

...and as Dlf has suggested, check that you aren't adding more Ammonia via Chloramines in the top-up water and therefore adding to the Nitrate level with each top-up.

Sounds like you need more growbeds....

My systems stay at 40ppm, sometimes goes up to 80ppm.
The last check was that ammonia went up from 0.5 to 1.0ppm in both tanks.