|
| i run drain to waste
res
medium (rockwool) sample
waste water sample
is this an indication that im feeding to much? is it ideal to have all them read the same or is the waste and medium generally slightly higher? |
Follow-Up Postings:
|
- Posted by Cole_Robbie none (My Page) on Tue, Aug 28, 12 at 0:13
| Nutrient salts are going to accumulate in any media that you run the nutrient solution through. It would be the same with a bucket of dirt. Just watch your plants and see if they are showing the effects of too high of a nutrient concentration when they shouldn't be. You may have to flush out the rockwool with pure water every so often. |
|
- Posted by Cliver-McGuiver none (My Page) on Wed, Aug 29, 12 at 8:26
| I performed a small test... 1 - 25 Lt. pail of nutrient solution at Add 1 ml phosphoric acid Add another 1 ml. of acid Electrical conductivity increases with PH level decreasing. Maybe your tap water has a lot of calcium/lime in it and as the plant takes it up the PH increases. |
|
| Cliver, wouldn't you reach a similar though inverse conclusion if you added calcium or potassium to raise the pH? After all you're adding a compound to the water to lower the pH which will also, naturally, increase the EC as you're adding a dissolved solid to the solution. buster, I think your first assessment is probably correct. your plants are likely transpiring more water to cool off than they're consuming nutrient thus the run-off water has a higher level of dissolved solids. Ideally, you'd want any run-off the have an EC of zero (meaning all the nutrient is consumed) but I think having the in and out solution match or the out slightly lower is a more realistic target. |
|
- Posted by buster1234 none (My Page) on Wed, Aug 29, 12 at 12:19
| PH is stable drain to waste ph in res never changes since the water is always new and never recirc so the ph isnt likely to have anything to do with the EC rising ... i set the ph at the start of a new res and im done never to ajust it again until the res runs out as for over feeding.. i have tried feeding as high as EC 1.8 and havent seen any sign of toxicity or leaf curl except i have seen less fruits with taller spindly growth from the higher EC.. therefore im not feeling confident o leing the plants tell me cuz there not telling me there just producing less i suspect the plants just stop obsorbing/transpiring as much fluid in order to reduce the take up of the higher than ideal salts = reducing mineral uptake =reducing flower set and yield as well as the high ec having high N levels for example on peppers high N = less fruit |
|
| I wouldn't think pH would matter, in absolute terms, to EC. That's because pH is a measure of H+ ions. In practice we are looking at H+ and OH-. If you add HCl to decrease pH you are still adding Cl- which will raise EC. If you were to add NaOH to lower pH you are still adding Na+ which will increase EC. |
Please Note: Only registered members are able to post messages to this forum. If you are a member, please log in. If you aren't yet a member, join now!
Return to the Hydroponics Forum
Instructions
- You must be a registered member and logged in to post messages on our forums.
- Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review the contents and make changes.
- After posting your message, you may need to refresh the forum page in order to see it.
- It is illegal to post copyrighted material without the owner's consent.
- HTML codes are allowed in the message field only.
- No advertising is allowed in any of the forums.
- If you would like to practice posting or uploading photos, please visit our Test forum.
- If you need assistance, please Contact Us and we will be happy to help.