Backyard Aquaponics
A place to discuss aquaponics

Don'y you guys use at least new PVC for your pipework? I have taken the precaution of flushing these systems prior to use.

Short answer Al... yes... and there has been much discussion regarding this issue.... particularly with the newer "foam" sandwich stormwater pipes...

To those interested in solar collector,
I already had a scrrew joiner for the riser pipe to the solar collector from the pressure line, so I opened it up and to my disappointment saw appreciable amounts of water still taking this route despite the other valve on the main line being fully open. I'm sure now that this has been the cause of excessive heating in the daytime (ahead of ambient) and excessive cooling at night.
But this has been very recent and the solar collector has been in place a few weeks. I think the reason why it has just happened was because I have just increased the pump flowrate through the section.
Well I have now installed a valve in the riser to go with the one on the main line to stop any leakage into the solar collector when I don't want it.
Should now be fine. I'll advise if it isn't.
The only problem is this new valve it outside my fish shed and under the roof of the chook run so I have to make a bit of a messy detour to adjust it. I'm sure my wife will just say, well pick the eggs up at the same time, will you. :-))

Its called thermo syphen

Good point F&F but I thought all the water might have taken the line of least resistance and gone straight along at the same "altitude" if it had that option rather than some of it going upwards for 150mm or so and round a couple of bends...oh well, you live and learn

Anyhow, I had the pump to the fishes in the 1000l tank (75 maybe 300g silver perch) off for two hours while I added the valve with just my 20W air blower operating via 4 airstones. The fish didn't seem to have any problem with that.

Let us know the difference it makes to the temp readings AL.... please

Yes, it all seems under control again, and the fishewater is behaving like it used to, before I installed the solar collector (without a valve in the riser)

A couple of days ago, before I put the valve in the solar collector riser feed line, the air inside the fish shed dropped by 5.3degC from 21degC to 15.7C overnight while the water in the fish tank dropped 8 degC from 26degC to 18degC.
Last night, before I installed the valve, the air was at 25degC and the water at 28degC. I then installed the valve and over last night the air dropped 6.9degC to 18.1 and the water dropped 5degC to 23degC.....so now the water T is dropping less than the air rather than more. (suggests no solar collector night chilling).
Today by 1340h, the air T in the fish shed had increased to 24degC, an increase of 5.9degC but the fish water remained the same T as first thing in the morning(=> no solar heating).
BTW, the air outside the shed was 36degC to 42degC depending on which thermometer type I used.

A couple of updates on my system relevant to water quality and the topics discussed in this thread.
The good news for me is that the solar collector is now working very well and kept the 5000l of water continuously circulating in my system at an acceptable temperature in the low 20s in my system despite the fact that it has been relatively cool and rained most every day for weeks.
The bad news is that I introduced about 200 small silver perch (6g) into my other fish tank which has its own fitering system off-line of the main system only to start losing them within days.
The situation was similar to that when I first loaded my first tank with larger fish (150g) but in that case it took a month for problems to start and these coincided with the first connection to a growing trough in my polyhouse.
The fish developed excessive slimey appearance before passing on and I lost 30/100 of them before I got on top of the problem.
With hindsight I now believe in both cases that it wasn't pH, TAN or nitrite that was unacceptably out of whack but rather the introduction of several week "old" water into the fishes environment. This "old" water appears to have contained parasites.
In the earlier situation, I could only remedy the problem by several large dumps and renewals of the water because I didn't want to introduce NaCl to the plants.
In the recent stuation, I was able to both introduce salt (0.15%) and raise the water T up to 28degC. This rapidly fixed the problem within 24h, the fish became much more active and now losses are minimal. However, I noted that these small fish seemed much more sensitive to the problem than the larger ones and much more drastic and rapid action was needed.

You can go to 3ppm without hurting plants

Alchemie.... I take it by "old" water ... you mean water that had been laying stagnant, or at least non circulating for a couple of weeks in one of your growtoughs??????

Oh, and by the way.... did you get the new batch of 200 SP's from the same source as before..... how big were they and much did they cost?

Thanks, I might have to go a bit higher with the salt concentration because I am still getting the odd bit of flashing and the occasional fatality but everything seems to be getting back under control. The fish are darting around happily and eating OK.

I assume you meant 3ppt which others on the forum have also said is OK at least for strawberries. I read that from one fish care source that I could use 0.02 to 0.2% salt (ie 0.2ppt to 2ppt) while another said that 6ppt was OK.

As far as the plants are concerned Rakocy of UVI says that levels of sodium chloride above 0.050 ppt or 50ppm start interfering with the pickup of potassium by the plants which is well below your level of 3ppt.

Yes, in the first case with the larger (150g) fish, I hooked them up to the first trough in the polyhouse I was commissioning about a month after receiving them. In this case, the water in the polyhouse trough had been sitting idle for two to three weeks.

In the second case, the smaller (6g) fish were put in about a 3 week old tank of water that had been fitted with a couple of biofilters that had sat idle for some days and were being reused. The water was only being turned over slowly prior to the introduction of the fish and the parasites if that was the problem could have been in the biofilters or the tank water.

In both case, the fish started having problems within days of being subjected to the new environment.

Yes, I did. I originally wanted them in mid-January and was quoted $0.80 each but the supplier at that stage wasn't around for me to pick them up and then I went away. I picked them up on February 9th whereupon at 6g he said that they were bigger than when he quoted me but under the circumstances he would hold his price.

So far, I think he is a good supplier and the parasites were generated by me not him .

Did you take any Ph/nitrite/temperatue tests of the trough/tank water before putting them in Alchemie?