Hardness of your pond water and impact upon pH
I have heard from two readers very recently who decided to make adjustments to their pond water based upon pH measurements they made ...on this basis I thought let me go into this matter of pH more carefully and in a sense this is therefore a continuation of the previous special edition .....
NOTE THIS VERY CAREFULLY ... pH is an extremely complex pond variable. It is almost impossible to make an accurate adjustment even in the unlikely event you have measured the result correctly and you have taken the sample at the right time of day. So why measure it? .. well as I suggested before; don't
There are mathematical reasons and chemical reasons for this difficulty ... the maths problemis due to logarithmic variability and not simple proportional or linear variability but we are already getting too complicated.
The chemical reason is the result of what is called "buffering" and that is what we will talk about. Buffering is better understood by talking about hard and soft water which are terms most of us are familiar with.
Briefly buffering does what the word describes ... it buffers, insulates, minimizes, or protects against excessive pH variations in pond water due to changing acid or alkali content so that pH does not necessarily change too much when more acid or alkali is added to water. Pond water low in buffering capacity therefore can show large swings in pH when acid or alkali is added.
In general buffered water (hard water) is normally better for pond inhabitants ... more in a moment but lets talk a bit about fish stress first ....
Fish become stressed when their living environment (the pond water) changes significantly .... hence the recommended procedure for introducing new fish to pond water you will all be familiar with I am sure ... i.e. let the temperature between the bag water and the pond water slowly equalize by floating the bag on the pond and/or by adding small amounts of pond water to the bag before releasing the fish.
Trying to make changes to water pH by adding chemicals of any kind introduces stress. When fish are stressed they become prone to disease from lurking bacteria which are always present in your pond water. So do not create stress situations and you will lessen chances of bacterial disease problems. Large daily pH fluctuations also create stress.
HARD WATER ... what is it? learn a lot more here
The easy way to recognize if general hardness exists in your house is by washing your hands and face ... if it is difficult make a lather and if a scum is left around the basin or bathtub then your water is hard. If your, skin, hair and laundry is less bright than you would like it then you may have a case of hard water.
If lather forms easily and there is a slimy feeling to the water then the water is soft.
Of course you can measure hardness and this is probably one of those tests worth doing on pond water now and again... .but if you measure it make sure you understand the result before making any adjustments.
In gold fish ponds it is really unnecessary whereas with prize koi then it is worth doing with a high quality test kit.
When you measure hardness you are actually identifying the amounts of calcium and magnesium hydroxides, carbonates and bicarbonates in the water .. also called temporary hardness (because such hardness can be removed by boiling water which releases carbon dioxide and leaves insoluble calcium carbonate behind ... see the scale inside your kettle). By changing to a different test kit you can measure other types of hardness such as sulphates and chlorides ... referred to as permanent hardness.
Total hardness is the sum of both types of hardness.
In general it is good to have harder water (hard due to carbonates) in your pond because it assists greatly in controlling variations in pH and also prevents metallic impurities (such as copper which then becomes insoluble) becoming a significant problem for your fish. In addition hard water helps a fish to regulate its own metabolic processes and reduce stress somewhat. Hard water is normally on the alkaline side of pH ... i.e. more than 7
To try and give you a feel for how much pH can vary in a planted pond or one with algae growth (source of carbon dioxide during night) consider the following general statement ...
If pond water just before darkness falls has a pH of 8 and a low hardness of say 0.3 and carbon dioxide released by plants or algae amounts to say 5 units overnight then the pH at dawn might be as low as 6.8 because the released carbon dioxide is naturally acidic. Now if the same water with a pH of 8 had a hardness of about 2.0 then by dawn the pH would have fallen to only 7.5 due to the same amount of carbon dioxide being released. The hardness has "buffered" the water from excessive pH fall.
This process reverses itself during the daylight hours.
So you can see large swings in pH result from low hardness values.
Yes water can also be too hard and this situation assists in the formation of string algae or blanket weed which is a curse. In very hard water pond keepers get excessive algae build up on the sides of ponds).
Softening hard water where you have string algae problems can help. You soften hard water by mixing soft water ... e.g. from a home water softener unit (see Pond Professors pages on this subject here)which many homes have.
Water hardness can be improved by adding sodium bicarbonate and I have seen it suggested that the best material is calcified seaweed ... here's a description I found on the web ...
Calcified Seaweed is a calcareous marine algae resembling coral, known to marine biologists as Lithothalium Calcareum. It is dredged from the seabed mainly off the Brittany coast, dried at low temperature and crushed to a fine powder, which is readily assimilated by the soil. It contains about 46% calcium oxide, 5% magnesium oxide; sulphur, copper, iodine and cobalt and some twenty trace elements. It is an ideal soil conditioner and clay breaker and can be used on lawns, beds and borders as an alternative to 'lime' to correct soil acidity. It is highly favored by chrysanthemum, sweet pea, dahlia, leek and onion growers. It is non-toxic and safe to use does not scorch and stores well if kept in a reasonably dry place.
2. Pond plants for this season
Pond plants ... every garden pond should have some (even those small barrel ponds I discussed last time). Here are some suggestions for this season and where you can get them on line ... click the image banner below and then choose Water Plants once you get to home page
They have nice basic variety of water lilies for sale ... every pond should have a water lily or two. There is also a wide range of marginals too. Well worth a look Other plants available ... see the pictures at my web site by clicking the linklink not placed here to reduce download time
3. I amhappy to help ... if I can
I do understand that many people have difficulty specifying correct equipment and even though I have tried to reduce the burden and unknowns it can still be a bit daunting. Here's a bit of help Bob requested this week along with my response ...
I have a Koi pond that I need help. I use a Tagalus sand filter with a 1 HP Dynamo pump that is broken. I was thinking of replacing the Dynamo pump with Whisperflo 3/4 HP. The pond is approximately 240 cubic feet (12 x 8 x 2 feet). I have a waterfall feature that is about 5 ft high.
The pump/filter is in the garage and the water must travel at least 35 feet to the pond. This was originally done so that the pond could be enjoyed without the grating noise of the filter/pump. I would be interested to hear any suggestions you might have. For example, separate pump for waterfall, etc etc.
Thank you in advance,
Bob
Info@pondsandpumps wrote:
Bob
Firs of all I am totally against sand filters for fish ponds. They contribute to significant disease problems and create unnecessary water wastage and power costs to any pond system. Quite simply it is impossible to keep these filters clean because of water channeling that creates anaerobic conditions. They increase plumbing costs dramatically also
The pump you use is a good example ... noisy, expensive to run and filter needs frequent backwashing probably. For a pond your size there are very good submersible pumps made in USA
If it was me I would do the following ....
Replace the sand filter with fairly conventional box filter with good biomedia (the best low cost biomedia by far in my 11 years of experience is called Alfagrog (Supra in USA). The cost to suit a pond of your size is small see All about pond filters
Biofilter capacity can be increased by adding more media. If you do not have UV I suggest getting combined Fish Mate Bio Filter and UV as you will see on the site above
With such a filter arrangement and your waterfall of 5 ft you have 2 good possibilities ....1 To save maximum power run a single pump that will deliver between 500 US galls per hour and 700 galls per hour to filter placed at ground level 24 hrs per day (this is absolute must for biofilter). I would recommend highly efficient low cost Danner pump ... see
Choose the right pond pump and choose either 3rd or 4th in list you will see there. You will need to then run a second pump to feed waterfall on separate pipe and switch on only when you want to (this is how you save lots of money). Waterfall pump can be based upon following .....
Width of waterfall overflow lip in inches x 50 US gallons per hour (so if waterfall 10 inches wide a good flow would be 500 galls per hour). This flow must be available at head of 5 feet + another 1 foot say for pipe losses ... so 6 feet head. Pipe must be 1 inch minimum diameter You can also choose a very reliable USA made Danner pump from same site ...
2. Buy pump that will deliver flow required by waterfall and push all through the biofilter which would then either be placed above waterfall. As alternative to this the flow could be split thereby allowing biofilter to be placed at ground level ... you would need to regulate flows using valves ... with separate pipe going to top of waterfall. Flow required would be total of 500 galls for biofilter and that required by waterfall as described Once more choose from
Also take a look at this pdf file for selecting correct Danner pump more accurately where you have a waterfall measurement
If you are not sure send me width of your waterfall overflow and I will give more accurate pump spec for you
If anything not clear let me know
Tony
Bob replied
Gee Tony thanks! So much information and your time. I live in Cerritos, CA. Any chance you know someone I could pay who could help me? I find that finding a reliable, cost effective pond person is one of the most difficult tasks I've ever had! Bob