Hi all, new to the forum!

We purchased a home with a backyard pond about two years ago. I have been struggling trying to figure out how to improve the water clarity. The pond is ~1/8 surface acre, 3/4 acre-ft. There are a couple silver maple trees about 30' away, so some leaves, seeds fall into the pond, but really not that much and other than that over the year just a bit of other blowing leaves make it into the pond.

At first I thought I was dealing with planktonic algae but now I'm not too sure since the water is light brown. I list the leaf situation since I'm also reading this might be a tannin discoloring from the muck on the pond bottom?

Thoughts on what I'm dealing with and how to remedy (both short and long term) appreciated.

Looks like suspended clay to me.
Is it a clay lined pond?

I would start with jar test and ag lime.

Thanks, I don't really know, but we're in NE Illinois and my guess is yes the bottom is probably a clay base.

Fill a pint mason jar and seal it,Maybe take a picture of it for reference. Let it set undisturbed for several days. If it is clay or sand it will settle to the bottom and get clear. Faster it clears the less clay. Mine usually cleared within 48 hours. Compare it to your earlier photo. That might give you a start.

What else might it be if not clay?

https://www.amazon.com/clouddrive/share/...share_link_copy

Good article on suspended clay.

Welcome to PB RGC! If your pond has any submerged logs or fallen trees in it, especially if they were put in less than a few years ago, you might be dealing with tannins. I put hedge stumps in my pond over a year ago and the water was dark tea colored at times, it seems like it has lessened this year. My pond collects a fair amount of leaves as well. I have not read that tannins cause any real trouble unless the source is from certain species of trees, I forget what species.

Here's a brief thread of mine regarding tannins...

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=36558&Number=477679#Post477679

Great, thanks. If it is suspended clay, does it make sense that the water is just staying this light brown for a long period of time since spring; basically unchanged? Uneducated guess is that it'd settle out but nothing seems to be changing. It was clearer after winter along the edges but that's gone now.

Suspended clay can stay suspended indefinitely in the right conditions.
(I speak from experience)

I used a heavy dose of ag lime to bring the water chemistry to a condition that did not favor clay suspension, then nailed it with gypsum.
Huge difference.

If your pond is clay, you need lime.
It's $60 a ton in my area. Cheap enough, but slow acting.

Oaks are a source of tannins

From what I'm reading on this forum it seems as if everyone eventually ends up using alum/lime to clear up suspended clay water... a couple questions:

- our pond overflows into our neighbors and they swim in it at times... what are the effects short/long term of alum/lime on the water relative to swimming in it?

- where are typical places to buy these two products? i've read other threads and it seems farm coop/feed stores, but wondering in general what the options are

- for my pond (~0.8 acre-ft) looking like I need about 100 lb alum, 50 lb lime?

My pond is just at 1 ac/ft. I put in 500# about 8 weeks ago. Will probably add another 500# this fall. I dont think you can put too much. Just make sure its ag lime and not hydrated lime. I initially went to my local feed store for it, they said at first it was ag lime, turned out it was hydrated. Tractor Supply carries 50# sacks if you cant find anyone who can deliver a truck load. My understanding is most truck deliveries typically require a minimum quantity which may be much more than you need or want to put in.

Thanks, what can be said about short/long term "safety" of alum/aglime treatment to water in terms of swimming?

Don't know about alum, but lime settles pretty quickly. Once it's on the bottom swimming isn't an issue as far as I know.

From what I've read ( but don't rely on this) alum acts much the same way, since it attaches to suspended clay and settles it on the bottom.

I'd think after a few days you should be fine.

Ag lime is not a water safety issue. It only adds to the water up to ph. 8. It is much less of an issue than chlorine that goes in all swimming pools.

Thanks all. So yesterday evening I added 50# alum, 25# aglime to 1/2 my ~0.8 acre ft pond. Poured 12 5-gal slurry buckets over the aerator on one end of the pond. Didn't see much action until this morning when there started to be some dark streaks forming that (I'm hoping) were streaks of clearer water. Right after that we had a fair amount of rain for a couple hours and by mid afternoon I have poured 12 more buckets of the same (100#, 50# total) over the aerator on the other end of the pond. I'm turning the aerators on and off every couple hours for a bit yet today to keep the mixing happening.

So my question is to ask if this all sounds pretty normal? Anyone else experienced, or can explain how their water cleared up? I'm hoping to see some satisfying results over the next couple days!

What did your jar test show?

Well, jar test in a 5 gal bucket revealed I needed ~1/5 tsp alum to clear the water in ~30 minutes. If I have the numbers right... that works out to 1/25 tsp alum/gal water, so for my 250K gal pond I need 10K tsp which I think is in the neighborhood of 130 lbs of alum (using .013 lb/tsp for table salt). This also agrees pretty well with using ~100 lb for a 0.8 acre-ft pond.

So that all seemed good, unfortunately after posting yesterday we had a crazy downpour and washed a whole bunch of new runoff (that I'm working to control) into the pond... in the end I'm back where I started and will need to do this again! Ugh.

Here is an update on my pond progress. On Sunday, I mixed 700lbs of Alum in trash cans with a trolling motor. I threw half of it from shore and the other half from a boat. I also did the hydrated lime. I only treated one half of the pond, but there was a good wind which I believe carried the Alum to the other side of the pond. When I was finished I noticed absolutely no difference.......I left thinking I hadn't applied enough.

I returned three days later to check on things and the second picture shows you what I saw.

FYI. It was granular form. It mixed well. About 30 gallons of water to 50lbs was the ratio I used. It was easy to handle that way. It was a lot of work, but wow.......did it clear my pond.

Thanks for the pics ! They show the results well. I am copying the info into an archive type thread.

I noticed the OP used Ag Lime with the Alum....it should have been Hydrated Lime!!! The Aqua-marine color, as Bob Lusk pointed out to me is due to a very low pH from the Alum....Ag Lime works VERY slowly to raise/stabilize pH...Hydrated lime at a rate of 1/2 by weight to Alum will balance the pH once both are applied....I'd be surprised if there is not a near total fish kill from essentially using straight Alum to clear the pond....this is not a good thread for reference, IMO

What am I missing. OP (RGC3) did not post the aquamarine pic as that was a different pond ( in VA not ILL (OP address). Poster (mglanham) with aquamarine water did use Alum and hydrated lime not ag lime. Confused here.

Refers to this post....maybe he used hydrated lime.....It was RG53 that said 50#alum and 25# ag lime......the color it was is indicative of a really low pH though...hope it was fishless water

?? the aqua pic refers to a pond using hydrated lime and Alum not ag lime. Were the amounts wrong ?