Good General Pond Design and Care Advice
Hi Peter ... Impressed with the book (nice being able to use the PDF version before the post arrives), have now started to dig the new pond
I would like to ask your views on Filtration as I am a little confused at the moment; for background info:
1. Having to create a new pond as we are having an extension to the house being built in June. (pond was here when we arrived I have never constructed one)
2. Existing pond has around 18 fish most are gold fish at least a couple may be Koi (over a foot long)
3. Existing pond has no filtration and the water is fairly green (at least the herons cant spot the fish so easily)
As I understand it setting up a koi pond is in a different league when it comes to depth of water and filtration systems. (and this is not what I whish to create)
The intention is to create an attractive pond with clean water and some fish for interest!
I estimate the pond to be a little over 4000Ltr and had been considering one of the fibreglass 4 bay filters with a Vortex - (to be gravity fed) this seems to be a fairly convention method
Disregarding the Garden Centre Pump Filter systems for 50 to 80, I see from the internet that there a filters on the market that advertise no maintenance or filter media replacement by virtue of a back wash system, and are easily hidden as much smaller in construction. (see attached)
What would be your advice?
Best Mark
PS have already recommended your book to a friends husband who is about to embark on a pond
Hi Mark ... The evolution of a pond, particularly with large fish in, is for it to always end up as a murky mess. In fact merely a bog. The only things that will put a brake on that is sufficient plants OR a filter system or both. With koi in there, unless they have grown up from tiddlers in there, they are prone to making the water look worse than it is. And if there isnt sufficient plant life in there, any additions are liable to pulled up and messed about by the koi. They think you are giving them a toy to play with. Many koi keepers depend entirely on a filtration system and dispense with plants altogether. Yes having koi is a very different hobby to normal fish ponds- they aint natural! And they're expensive
Koi are also not happy in pools less than 1metre in depth.
First of all, check on the health of the water. See how much sediment is down there. Try to a water test. Particularly pH.
One of the rules for the quantity of fish is 2ins of fish for every square foot of surface area. There are others, but that is the one I grew up with. 45cm to the sqmtr will do. Any excess of this will induce green water, no matter how many plants you have.
To keep the water clear with just plant life you need a complete cross section of marginals, deep water plants like lilies and most importantly oxygenators. You must aim for two thirds pool cover. If you want to see more of your fish you need to resort to a biological filtration system which is like a 'turbo' version of a pond bottom remote from the pool. It allows you to break the rules to a certain extent and irons out the merrygoround caused by fluctuations of weather. The bacteria in a filter are the same as in a pond. They digest organic matter but need a constant supply of oxygen to do it. Therefore a biological filter must run 24/7.
For koi ponds in particular the rule used to be that the size of the filter
needs to be one third the surface area of the pool. With new types of filter
medium this is not quite so necessary, but it is worth bearing in mind. For any
type of fish pond, what you must do is recycle the total volume of pool water
through the filter every two hours. Preferably put a U/V lamp in front of the
filter. Therefore with your 4000litre pool you need a pump that is capable of
handling a bit of muck and shoving it through a filter at 2000litres per hour.
Your local dealer will help you choose a suitable pump. Take note of the power
consumption when you are weighing up the costs. This is quite a a significant
factor in the long term costs of the pump.
That Vortex style of filter is very good although they tend to be bit on the
large size for a 4000litre pool. Maybe you are considering a 4000gallon pool in
your next venture!
The filters you are looking at do work, especially if you get the uprated versions with uvc included. Also go for over specification and dont believe that crap about them being maintenance free, or not having to clean them out. Oase make the best one, then fishmate, then Hozelock. Tetra are new on the block in this field, but instantly lose credibility if they make stupid claims like that. The CAL filter is new to me, so I dont know. They are easy to hide, which is important in a small garden, but they are not quite as fool proof as the header tank style - which if it is top fed and top dispensed into the pond, can also be backflushed.
I hope all these points answer all your queries. And thanks for the recommendations.
Good luck