Pond Boss Forums GENERAL QUESTIONS Muddy water Cleaned pond water is now grey color.

Hi, this is my first post so hello all.

We have a small natural pond at the top of the garden, I say small because of some of the sizes mentioned in the forum but for us its big, it holds about 200,000 litres of water.

Going back a couple of weeks we totally drained it to give it a good clean (first time we have done it since buying the house). We removed all the decomposed matter at the bottom and took it back to the natural clay and rock. The problem now that we have filled it again is the water has turned grey (it was very brown before the clean). I have put some water in a glass jar and it has not settled after a few days of standing.

I wonder what is going to be the best method to clear this, I'm not sure because most posts I see here relate to brown water.

I was going to try some water test in jars but the links I have found in other forum posts do not work so I'm not sure the ammounts to try. I think I have some gypsum, its a powder type stuff my wife uses for moulding in her work, I take it thats the stuff I need?

Thanks, Adam.

Razoola, welcome to the forum! It's great to be getting an international flavor here.

If you cleaned out the "muck" in your pond, it is most likely that you also removed most, if not all of your established beneficial bacteria and left behind nothing but the anaerobic bacteria that was under the muck.

This anaerobic bacteria are slow acting in helping with decomposition and often release toxic gasses like hydrogen sulfide into the water.

The condition will likely clear itself in a few weeks as the bacteria re-establish a balance.

Do you have fish in the garden pond? If so, keep an eye on them for signs of stress and be prepared to replace some of your water (50-75%) if they appear stressed or begin too die. Once again, once your bacteria are re-established, this concern will diminish greatly.

Adding some Gypsum and/or Ag/pelleted lime (Dolomitic Limestone) could help and often have other benefits as well.

Best of luck with the cleaning and please keep us updated on what happens.

There are natural carp and koi in there, not many though and thus far they all seem very fine.

The water turned grey during refilling, I take it that its simply clay particles, its not something that came after a few days, the crystal clear water turned as it filled. I forgot to mention I have three airstones through out the pond and I suspect this did not help and probably the cause of the problem? In the simple jar test I did the particles stayed suspended after a week of being there and show no sign of dropping.

Is the type of gypsum I have the correct type to add (used for moulding)? I have found some info about how to caclulate the ammount to use but the instructions talk about adding 2 tablespoons to a gallon of water and then mixing into a slurry before adding tablespoons of that mix into test jars with pond water. The problem for me is the first part, when I add that small ammount of gypsum (2 tablespoons) to that much water (1 gallon) it does not turn into a slurry, the water simply turns slightly white and nothing more. Is that what should happen before I use it in test jars of water? I would have assumed if it were to go into a slurry it should be thicker?

Tervetuloa minun Suomalainen serkku,

Glad you could join us.

I'm unfortunately unable to give you an answer to your question, but we have a lot of experts here.

I just wanted to welcome you.

Monnipoika
(Ken)

Razoola,

It may indeed just be suspended clay....is your clay grey colored?

You mention a problem with creating the test "slurry". The slight change in color IS the slurry. Slurry simply means that the gypsum does not truly "dissolve" in the water.

You may want to add ag lime (dolomitic limestone) along with your gypsum. Niether gypsum nor Ag lime can be "over" applied, just under applied.

PS

Common carp and Koi will stir the bottom sediments browsing for food.

Yes the clay is grey colored. This is original clay thats in the soil around these parts and not something that was added to the pond to seal it.

I have already added about 25kg of calcium carbonate to the pond to help raise the ph (currently about 200,000 litres in the pond). I have done some tests with the gypsum I have but it seems I need to use alot for it to work. The test pond water clears if I add a 1 deci litre measure (5th of a teaspoon) of the powdered gypsum to 1 litre of water (about a quart), stir it and leave it for 12 hours. This is way more gypsum than the test I have read suggests which makes me wonder if the gypsum I have is the right stuff or not.

The gypsum I have was ordered from a building yard about a year ago, its classed as model gypsum. My wife uses it in her work for making casts. I'm just not sure if this type of gypsum has alot of other stuff added or not. Does it sound the right stuff to you?

One other thing you may want to try that will clear the water very rapidly is Aluminum Sulphate. You would only need about 2-5 kilos and could get it whereever food spices/canning supplies are sold under the name Alum....It is used to keep vegetables crisp when canned.

It won't be the least expensive way to get Alum, but you only need a small amount. If your water PH is at 8.2 (Calcium Carbonate Maximum) you should not need to worry about the PH being lowered when you add the alum. Just add it slowly mixed well in clean water.

When applied at the right concentration, it will turn your water crystal clear in under 24 hours.

I have been looking at the posts regarding alum and I'm a little concerned about fish kill. Our PH is about 7 only, how does it affect plants also (water lily)?

It won't effect the plants at all. If your PH is 7.0, you could use more ag lime and/or gypsum.

You can offset the potential PH drop caused by alum by using HYDRATED lime, usually available where you get fertilizers or at feed stores. Sometimes you can get it at concrete plants.

Use 50% by weight of Hydrated lime of the weight of the alum used to balance the PH.

Apply the alum first, then just sprinkle/broadcast the dry Hydrated lime powder onto the water. Alum lowers the PH over several minutes where the H lime is almost instant in action and will neutrilize with the alum.

Thanks for the info.

I have got a 20kg bag of gypsum earlier today which is 85% gypsum and 5% calcium hydroxide (the lime you talk about). I think I may add this tomorrow to the pond and see what happens. If there is no improovement then I'll pick up some alum on monday. I feel it can't hurt any to add the gypsum. Do you think its adviseable to turn off the areation while adding gypsum also like alum? I just wonder if its good to add the gypsum with areation on for 30 minutes at full blast and then turn off given I have a smaller pond.

I have found a source for the alum but need to find a source for the hydrated lime.

Aertion will help dissolve the gypsum. If you use the alum later, I would turn of the aeration for 24 hours to allow the floculation.

Im going to add the gypsum in the next couple of hours.

I don't know why I did not do this before but here are some pictures of the pond clean I did in a small picture diary (and some older pictures of the pond too) at (pictures removed). Some of the pictures are big.

The current water color situation is almost the same color as day12 end of pond clean.

Neat looking place

All that rock would look awesome in clear water!!!!

Thanks, our place is quite unique, we live on a hill and the pond is above the house

My plan is to try and get the rock showing through clear water. I suspect I will need to diy some kind of pond vac though to be able to clean the rock once in a while, a type that will pick collect silt and particles and not leaves etc.

I added 20kg gypsum this morning. Its been about 10 hours now and the water clarity has improoved from 8cm to about 13cm. Im not sure if it will continue to clean it more or not. If not I'll probably add another 20kg on Monday.

Razoola,

I'm far from being an expert in this area, but I really think that your pond will clear on its own if it is from the clay.

When I look at your "old pictures" the water looks absolutely perfect. I'm assuming it is brown from the tannin produced by tree roots and tree leaves around the pond.

The photos are beautiful, and your place looks extremely inviting.

It is possible that the carp and koi are stirring it up. But, if the water was relatively clear, except for algae and tannin before the cleaning, I doubt that is the case.

I think that your pond is acting like a recently formed or recently dug pond. There are a lot of extremely fine clay particles suspended in the water. It will just take time to let this clay settle out.

I don't know what part of Finland you are in, but I can only assume your pond will start to ice-over sometime in the next two to three months. I know it is a long time to wait, but ice and cold have a way of really settling a pond. I would estimate that by springtime when the ice melts, your pond will be clear of the clay.

You may have to "enjoy" the brown water if it is from tannin. From the older photos, it looks like you've had good plant growth in the pond. The plants will help take up nutrients, thus control algae formation.

Lastly, where does your lampi vesi come from? Is it above ground runoff, a spring, or some other source like a pieni puro? Is it bringing impurities or too many nutrients?

Ystävällisin terveisin,
Monnipoika

Indeed the water was a brown color from what we believe was tannin given the ammount of pine trees around. Given that we bought the house with pond already there we did not really have an understanding of the bottom layout etc which is why we drained it and cleaned it in the last weeks. Its a good thing we did given some of the rubbish in there and ammount of non decomposed stuffs under the top layer of silt. Then there are the amasing rock formations, its clear at some point in the iceage water ran through the lengh of the pond.

There were alot of small carp in there and we probably let some 300 go in the local river (where they originally came from according to the previous owner). Hopefully this will help clarity also.

We are in southern Finland (Masku), there is no local spring where we can get water, we do have a 5 metre deep well but its close to a main road that gets salted and gritted in the winter so I would not like to trust the water quaity from there. One day I will have it tested. Everything going into the pond is either tap water, rain water or run off from the rocks behind. I do plan to clean the rock behind the pond later in the year of pine needles and cones and just leave the mosses if possible without making it look to non natural. I also plan to remove some trees (visable in day12end picture), there are a couple of bigger ones close together and I think taking one of those won't be a problem for the wife Will make some good fire wood for next year too!

We have never had a problem with either algea or weed thus far. I think given the rock base in many parts of the pond keeps the water tempreture lower than the norm, it probably keeps it a little warmer in winter though. The highest tempreture we had this year was 24c for a couple of days, the neighbours pond some 500m away is on average 2c warmer than ours. That said they lost all their fish last winter and we only lost 2 that floated to the surface.

I am sure the winter icing will help much with clarity as the water has always been clearer in spring, I want to try and improve the water parametres as well improove clarity some before the winter starts. The average ph around masku is 6 with very soft water. I want to try and maintain a ph of 7 with harder water. The calcium carbonate and gypsum we have added has done a good job in that respect, hardness has gone to normal though ph is still lower than I would like, its about 6.7 currently.

Just to update on the gypsum I added yeastuday, the clarity is now 17cm from 8cm before application but still greyish color. Before we started the pond clean clarity was 22cm with brown coloring. I think adding alum is not going to happen now which in a way I am happy about given potential fish kill, probably another application of gypsum only and then calcium carbonate as needed to maintain ph.

Razoola,

I would add plenty of extra calcium carbonate. It will help the pond by letting your aeration decompose everything faster, add calcium hardness to the water, help to clarify the water, smooth out daily PH swings and more. The highest it can possibly raise the ph is 8.2, a very tolerable level for fish. With all the pine trees, you will always have an acidity problem.

Just to keep you updated on the clarity situation.

It's now up to 22cm which is the same as before our pond clean. I am over the moon to reached the same clarity again given the situation after partially re filling the pond (2cm). Now I keep fingers crossed it continues like this for another 24 hours or more, would be real nice to hit 30cm tomorrow morning.

It seems I incorrectly thought the effect of gypsum on clarity would stop after 12 hours like in the jar tests but it appears to still be working here at least. Clearly not as fast as alum but its working.

Razoola, any update on your pond clarity?

It is currently at 25cm. My wife said she could see it down to about 28cm on a sunny day but I have not had the chance to test myself on a sunny day as I'm back at work now. Hopefully I can do it later today as it looks like we are going to have some nice weather.

Its been a couple of weeks now and we have just had alot of rain which has helped almost fill the pond back up. The water has gone a little brown because of that but the clarity is still around 28. Here are some pictures...

(pictures removed)

Presently I'm a little concerned because the water level was about 40cm below filled and it stayed at that level for a couple of weeks with no rain. But after the few days of real heavy rain last week it filled the pond 35cm of that 40 remaining. Now just three days with no rain the water level has dropped about 6cm. Is it possilbe this ammount or loss could be due to the surrounding muds sucking the water given the pond was drained to be cleaned?

Hey guys, I a new member and I have a problem. I have 1/2 acrea pond and it's not spring feed. So usually around this time of year it gets low. It's really low this year but not as bad as it was 2 years ago. I have some 3-5 pound bass in the pond and they are dieing. I guess my pond has turned over ( I don't know much about ponds) What can I do I have pulled out 12 dead ones out of my pond the past 2 days. PLease tell me there's an answer w/o all my fish dieing. thanks

Razoola, yes, the water could be absorbed by the soil. Once the soil surrounding the pond is saturated, then the water level should stabilize. Another thing to think about is evaporation. In my ponds by the house (300 and 100 gallon plastic tanks sunk into the ground) I will lose an inch of water a week to evaporation.

Karl:

Welcone to PB! If you would, go to the new members forum and introduce yourself. Tell us more about your pond, how old it is, how deep it is, what fish are in it, what the water looks like and what weeds are in it. You'll get better visibility of your question if you start a thread in the Question and Observation sub-forum.

Razoola, Yes, since you drianed your pond, the outer soils could have released the moisture they held and could easily be re-saturating.


Welcome Alabama Karl. Sorry to hear you are having troubles. I'd suggest starting your own, new thread under the "New Members" section and tell us all you can about your pond and fish---age, depth, species, sizes, watershed, etc. It will make it much easier to offer some reaasons and solutions for you.