Hi guys.
I'm having a problem with my pond ph level, as i understand 7.4 is considered optimum but koi will do fine in water upto 8.5. My problem comes in that the municipal water that i'm using is already at 8.5. The water in my pond is in excess of 9. I've been loading my pond with Bio Vital but it doesnt seem to lower the ph, jus keeps it steady. The thing is that if i lower it sucessfully without causing shock to my fish, the next time i top up i'm going to add water with a high alkalinity all over again! Any advice? Koi arent looking very happy, need urgent solution

Always difficult to lower pH. You can use pool acid or vinegar, but I believe it is dangerous.

Some people use lemon juice but it is expensive.

If you can get hold of peat moss or almond shells, it is quite safe.

The problem you are going to have is, you alter the pH ony to come back to 9, and maybe even cases a crash.

A high fall in pH is worst than a pH of 9.

Keep your algae to the absolute minimum as it will increase the pH. Also keep your ammonia to abosutely nil as it will kill the fish due to the high pH. Increase your filtration.

Try to get a different source water. Although it is not good to use rainwater from your roof, in your case it would be better. Install a water tank and channel your rainwater to the tank for use in your pond. Just add a bit of Virkon S to the tank from time to time.

What are the symptoms of fish that die of KHV? Can a really high ph kill fish?

First of all test for Ammonia and get all your parameters right. I suggest that you make Ph buffers and put them in a fast flowing area of your filters. Yes, a high Ph can kill koi. Also only buy fish from reputable Dealers and not from Pet stores as they rip you off and only sell pond muts that's infected with desease.

I'm loosing fish almost every second day. All of a sudden also cos they were fine and I haven't added a fish to the pond in the last month. Tested the water myself and the nitrates and salt content tested by two dealers aswell. All seems to be fine, then took the fish that just died and one that was behaving strangely for scrapes at both koi farms but nobody can see anything wrong with them!! The only parameter that's out of normal is the high ph, but then should they not be able withstand ph of up to 10?

It started when I noticed few fish not coming up to feed, then noticed the sick fish not moving around much, just sitting on the floor of the pond but fins not tucked? After a day or two they hang out just below the surface of the water now and then gasping or sticking their heads out of the wAter, the one fish mouth was stuck wide open. Once that happens it's not long before they tip upside down and within a minute they die. Please help

Hi,

If the pH is high, it will burn die gills and fins of Koi!!!

The gasping by the Koi is an indication that there is a shortage of oxygen, in your case it is not a shortage in the water itself but as a result of damage or suffering gills.

You could use pool acid safely by adding it to the pond with a “hospital drip” line starting with about 10 drops per hour. Check the pH reading every 12 hours, adjusting the drip with five more drop per hour. When the pH drops 0,5 every 12 hours it will be ideal, stop the treatment when the pH is down to 7,5.

Do not let the pH drop more then 0,5 points in 12 hours!!

Dear Mahmood,
Sorry I am replying so late... Hope it will help in any way.
I am going to state what is my experience with PH.
I have a constant PH=9...never bellow, maybe above, but I can not know that since my test measures up to 9 only...
I came to SA and bought 30 fish in May 2011.
Put them in a pond with no filtration...
Had lots of problems...mouth infection, ulcers...fin rot...but managed some how...(water changes) Build a filter, cycled it...and never lost a fish due to disease. This problems were caused by bad water quality ( N derivatives and stress)
Medicated them, injected them, cut bones, stitched them, burned them...but all survived My medication and all...
Lost 2 fish...one jumped...and one I overdosed by accident ( did not calculate the dose of the med well...rushing, and caused kidney failure...) For short I killed it...
For the past 6 month, I dont have any problems...my fish are healthy...and have spawned 3 times in one month...
My PH is HI and that is because of the source water and concrete pond..
My personal advise to U is{ from my limited experience}
Check your KH and GH....make sure U have at list KH of 120ppm. KH is calcium content, that helps buffer your PH...
If your KH is low U need to raise it...not to have PH fluctuations or crush.
I would personally not play around with the PH. Ones U start U will never stop...Hi PH is not too good but is not too bad either.
If U start adding acid, U can easily cause a PH crush...
Constant PH , even if it is high is not as bad as change of PH more that 0.5 in one day...
So I can tell U the High PH U have is not the cause of the death of your fish...unless combined with other factors.
U have a different problem, and U need to give Us more info in order to identify your problem...
Give a full description of Your test results, pond size, filtration...symptoms...
Have U checked the color of the gills?
Did U take the fish to the same dealer U bought it from??????????
Give Us more info so We can try to help.

Hi..
Okay the reason why assumed the ph to be the cause is because there were no other signs. I took my fish to two seperate deelers, did scrapings, checked the gills all fins and mouth was clear of any sign of parasites, no raised scales at all.

Secondly I tested my water Nitrates, PH, KH and i had my water tested at the koi farm and it was all fine except my PH that was like 9 or higher...

My pond is bout 4.5m * 2m and bout 1.2m deep, about 0.6m undergound and 0.6m above ground. I'm using a .45kw speck pool pump, 3 bag sand filter, 2 bag sand filter, ultra zap bio filter, and 30w uv light.
3 bag filter - sand
2 bag filter - chopped up clay bricks
bio filter - bio balls

Using one bottom drain in the center, two venturis on opposite ends to swirl the water gently and a small fountain are my inlets.

Hi Muhammad!
Your pond is around 10 000 liters...I know U have this pond for some time now, U say your KH is OK but U dont say how much it is.
U talk of measuring nitrates....what about ammonia and nitrites?
Nitrates are the list cause for alarm, and the list harmful of all the N compounds...
When exactly did U buy the fish? and how long after U bought it , it became sick?
Have U had health problems before with the fish in your pond or it is since U brought in new fish.
Did U change your filter, or media recently?
How many fish and how large are they?
Do U have lots of algae in the pond?
Do U have air stones in the pond?
I can tell U I was told not to believe every thing I read on the net....so when I have a problem I ask atlist 10 people before I decide what to do...
I will tell U this: all told me the same: dont mess with your PH...
I would put in the 2 bag filter crushed oyster shell it will be better for U.
If your PH of the source water is 8.5 why does your PH go over 9? Is your pond new concrete pond that is unsealed???
What time of the day U measure your PH...PH fluctuates during the day...Try measuring morning and evening, see if U have any fluctuations?

Hi Muhammad

Some good advice from Neli.

However, I would not bother replacing the media in the sandfilter with Oyster shells. Oyster shells are used to raise pH and will never lower it. If you pH is high, the acid will "munch" the shells and thereby constantly lower or buffer it as long as acid is present. Once it reaches 7(no acid anymore), they will have no further effect except being a filter media.

You say that you have clay bricks in one of your filters. Are you sure they contain only clay? Often, bricks also have cement added to it to make it stronger. If so, it will leach alkaline and constantly raise your pH.

Shucks... I think i left out the most important info, my pond is only 3 months old. I sealed it using flow coat, fibre glass resin basically. Uhmm I'm using a Sera Pond Test kit. The ph scale only goes up to 9. And what it tells me about the kh is that I add drop by drop until the colour changes from blue through green to yellow, and the amount of drops I add will tell me the kh. It says anything below 5 drops is bad and I add 7 so thats why I concluded that is ok.

I'm not a 100% sure about the bricks being only clay without any cement.. What would you guys suggest replacing it with?

Muhammad wrote:

I'm not a 100% sure about the bricks being only clay without any cement.. What would you guys suggest replacing it with?

Proper koi filter gravel or purely builder's gravel or mix. Some people would say zeolite, but I only had bad experiences with zeolite.

Admin wrote:

Hi Muhammad

Some good advice from Neli.

However, I would not bother replacing the media in the sandfilter with Oyster shells. Oyster shells are used to raise pH and will never lower it. If you pH is high, the acid will "munch" the shells and thereby constantly lower or buffer it as long as acid is present. Once it reaches 7(no acid anymore), they will have no further effect except being a filter media.

You say that you have clay bricks in one of your filters. Are you sure they contain only clay? Often, bricks also have cement added to it to make it stronger. If so, it will leach alkaline and constantly raise your pH.

Hi Admin,
thanks!
Oyster shells do no raise the PH they raise the KH and buffer stabilize the PH...If I am not mistaken (I assume) his KH is around 90...so oyster shells will help stabilize it...and buffer the PH.
Ones his filter is cycled, the bacteria will start consuming calcium...and lower The KH.
Possibly if he has plants or algae he will experience some PH fluctuations during the day.
But he can always put a bag of shells in the bio filter and substitute the media with sand as U advised... Just imagine I drugged all my sand from south Africa....

Hi Neli

I have not tested it scientifically, but all the experts says that Calcium Carbonate in Oyster shells cannot be dissolved without Acid in the water. With a pH of above 7, their will be no acid present and therefore the KH can not release and therefore I say that it is senseless to add oyster shells in a pond with a very high pH.

Admin,
it makes sense what U say....

How is your pond doing?

I had the same problehm for three years. The brick/cement pond I have was leaching even though I had seven coats of sealer on it. And since it was connected to the main pond my fish started dying. (Now this was years ago)

I treated it with muractic acid, monitoring carefully, and this is the first year, since we connected thei brick pond, that I have not had to treat. Right now it is staying at 8.4 PH steady which is much better than 9.3. I invested in PH meter, wonderful, to keep quick and easy tab on the situation.

Got it on Ebay. You also have to buy 7.0 ph buffer to re-calubrate the meter from time to time. Haven't had a fish die, since.

koigal50 wrote:

How is your pond doing?

I had the same problehm for three years. The brick/cement pond I have was leaching even though I had seven coats of sealer on it. And since it was connected to the main pond my fish started dying. (Now this was years ago)

I treated it with muractic acid, monitoring carefully, and this is the first year, since we connected thei brick pond, that I have not had to treat. Right now it is staying at 8.4 PH steady which is much better than 9.3. I invested in PH meter, wonderful, to keep quick and easy tab on the situation.

Got it on Ebay. You also have to buy 7.0 ph buffer to re-calubrate the meter from time to time. Haven't had a fish die, since.

Darling, when I built my first pond, I new nothing...Never sealed the concrete in the pond and my water from source is PH 8.5....My test kit was measuring PH up to 9 only...but I am sure it went beyond that...
Never lost a fish...from the day I put them in the pond due to sickness.
Never had algae too...dont know why!